Library 


DEPARTMENT  OF  'llli:  iXTI-'HIOR 
UNITED  STATES  GFOLp(;iCA;L  SUJtVEY 

GEORGE  OTIS  SMITH,  DIRECTOR 


37O 


THE  FIRE-RESISTIVE  PROPERTIES  OF 
VARIOUS  BUILDING  MATERIALS 


BY 


RICHARD  L.  HUMPHREY 


WASHINGTON 

GOVERNMENT     PRINTING     OFFICE 
1909 


Engineering 
Library 


Engineering 
Library 


CONTENTS. 


Page. 

Introduction 7 

Scope  and  character  of  investigations 7 

Synopsis  of  tests 8 

Acknowledgments 12 

Source  of  materials  tested 12 

Apparatus 14 

Furnace 14 

Apparatus  for  measuring  temperatures 15 

Preparation  of  materials  tested 16 

Method  of  conducting  tests 17 

Fire  tests 17 

Quenching  tests 17 

Strength  tests , 17 

Results  of  tests 17 

Panel  1  (mortar  building  blocks) 17 

Panel  2  (mortar  building  blocks) 19 

Panel  3  (mortar  building  blocks) 21 

Panel  4  (mortar  building  blocks) 23 

Panel  5  (mortar  building  blocks) 25 

Panel  6  (mortar  building  blocks) 25 

Panel  7  (mortar  building  blocks) 27 

Panel  8  (mortar  building  blocks) 28 

Panel  9  (mortar  building  blocks) 33 

Panel  10  (mortar  building  blocks) 35 

Panel  11  (brick) 37 

Panel  12  (brick) 39 

Panel  13  (tile) 41 

Panel  14  (mortar  building  blocks) 42 

Panel  15  (mortar  building  blocks) .- 44 

Panel  16  (mortar  building  blocks) *. 46 

Panel  17  (concrete) 48 

Panel  18  (concrete) 53 

Panel  19  (concrete) 55 

Panel  20  (concrete) , 55 

Panel  21  (concrete) 59 

Panel  22  (brick) 61 

Panel  23  (granite  building  stone) 61 

Panel  24  (tile) 64 

Panel  25  (building  stone) 69 

Panel  26  (building  stone) 72 

Panel  27  (building  stone) 74 

Panel  28  (building  stone) 75 

Panel  29  (sand-lime  brick) 77 

Panel  30  (tile) 81 

Tables 85 

Bibliography 97 

80O525 


TABLES. 


Page. 
TABLE  1.  Panel  1:  Results  of  compression  tests  made  on  fragments  of  one-piece 

double-air-space  mortar  building  blocks  after  fire  test 85 

2.  Panel  2:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 86 

3.  Panel  3:  Results  of  compression  tests  made  on  fragments  of  one-piece 

double-air-space  mortar  building  blocks  after  fire  test 87 

4.  Panel  4:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 88 

5.  Panel  5:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 89 

6.  Panel  6:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 90 

7.  Panel  7:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 91 

8.  PanelS:  Results  of  compression  tests  made  on  fragments  of  one-piece 

single-air-space  mortar  building  blocks  after  fire  test 92 

9.  Panel  9:  Results  of  compression  tests  made  on  fragments  of  two-piece 

mortar  building  blocks  after  fire  test 93 

10.  Panel  10:  Results  of  compression  tests  made  on  fragments  of  two- 

piece  mortar  building  blocks  after  fire  test 94 

11 .  Panel  11 :  Physical  properties  of  brick  before  firing 95 

12.  Panel    12:  Physical   properties   of   hydraulic-pressed   brick   before 

firing 95 

13.  Panel  22:  Physical  properties  of  common  clay  brick  before  firing. 96 

14.  Panel  29:  Physical  properties  of  sand-lime  brick  before  and  after 

firing 96 

4 


ILLUSTRATIONS. 


Page. 

PLATE  I.  West  and  southeast  exterior  views  of  furnace 14 

II.  A,  Interior  view  of  furnace;  B,  View  of  back  of  panel 16 

III.  View  showing  method  of  quenching  a  panel  after  firing 16 

IV.  Diagram  of  thermocouples,  cold  junction  bottles,  and  galvanometer  16 
V.  Face  views  of  panels  1  and  2  after  cooling 18 

VI.  Face  and  back  views  of  panel  3  after  quenching 20 

VII.  Face  and  back  views  of  panel  4  after  quenching 22 

VIII.  A,  Panel  4  during  dismantling;  B,  Face  of  panel  5  after  quenching.  24 

IX.  Views  of  panel  5  after  quenching  and  during  dismantling 24 

X.  Face  and  back  views  of  panel  6  after  quenching 26 

XI.  A,  Panel  6  during  dismantling;  B,  Face  of  panel  7  after  cooling. . .  28 

XII.  A,  Panel  7  during  dismantling;  B,  Face  of  panel  8  after  cooling. . .  30 

XIII.  A,  Face  of  panel  9  after  quenching;  B,  Panel  8  during  dismantling.  32 

XIV.  Views  of  panel  9  after  quenching  and  during  dismantling 32 

XV.  Face  and  back  views  of  panel  10  after  cooling 34 

XVI.  A,  Panel  10  during  dismantling;  B,  Face  of  panel  11  after  quenching .  36 

XVII.  Face  views  of  panels  12  and  13  after  quenching. '. 40 

XVIII.  Back  of  panel  13  and  face  of  panel  14  after  quenching 42 

XIX.  Views  of  panel  14  after  quenching  and  during  dismantling 44 

XX.  Views  of  panel  15  after  quenching  and  during  dismantling.  ? 46 

XXI.  Views  of  panel  16  after  quenching  and  during  dismantling 48 

XXII.  Face  and  back  views  of  panel  17  after  quenching 52 

XXIII.  Face  and  back  views  of  panel  18  after  quenching 54 

XXIV.  Face  and  back  views  of  panel  19  after  quenching 56 

XXV.  Face  and  back  views  of  panel  20  after  quenching 58 

XXVI.  Views  of  panel  21  before  firing  and  after  collapse 60 

XXVII.  Face  views  of  panel  22  before  firing  and  after  quenching 60 

XXVIII.  Face  views  of  panel  23  before  and  after  quenching 64 

XXIX.  A,  View  of  stones  from  panel  23;  B,  Face  of  panel  24  after  quenching.  66 
XXX.  A,  Back  of  panel  24  after  quenching;  B,  Face  of  panel  25  before 

firing 70 

XXXI.  Face  and  back  views  of  panel  25  after  testing ' 72 

XXXII.  Face  views  of  panel  26  before  and  after  firing 74 

XXXIII.  Face  and  back  views  of  panel  26  after  quenching 74 

XXXIV.  Face  and  back  views  of  panel  27  after  quenching 76 

XXXV.  A,  Face  of  panel  28  after  firing  and  before  quenching;  B,  Stones 

from  panel  27 78 

XXXVI.  A,  Face  of  panel  28  after  quenching;  B,  Stones  of  panel  28 78 

XXXVII.  Face  views  of  panel  29  before  and  after  quenching 80 

XXXVIII.  Face  views  of  panel  30  before  and  after  quenching 82 

XXXIX.  A,  Face  of  panel  30  after  quenching,  with  all  loose  pieces  removed; 

B,  Back  of  panel  30  after  quenching 82 

5 


6  ILLUSTRATIONS. 

Page. 

FIGURE  1.  Diagram  showing  temperature  conditions  of  panel  1 18 

2.  Diagram  showing  temperature  conditions  of  panel  2 20 

3.  Diagram  showing  temperature  conditions  of  panel  3 22 

4.  Diagram  showing  temperature  conditions  of  panel  4 24 

5.  Diagram  showing  temperature  conditions  of  panel  5 26 

6.  Diagram  showing  temperature  conditions  of  panel  6 28 

7.  Diagram  showing  temperature  conditions  of  panel  7 30 

8.  Diagram  showing  temperature  conditions  of  panel  8 32 

9 .  Diagram  showing  temperature  conditions  of  panel  9 34 

10.  Diagram  showing  temperature  conditions  of  panel  10 36 

11.  Diagram  showing  temperature  conditions  of  panel  11 38 

12.  Diagram  showing  temperature  conditions  of  panel  12 40 

13.  Sketch  of  glazed  building  tile  used  in  panel  13 41 

14.  Diagram  showing  temperature  conditions  of  panel  13 43 

15.  Diagram  showing  temperature  conditions  of  panel  14 ; . . .  45 

16.  Diagram  showing  temperature  conditions  of  panel  15 47 

17.  Diagram  showing  temperature  conditions  of  panel  16 49 

18.  Diagram  showing  temperature  conditions  of  panel  17 *  51 

19.  Diagram  showing  temperature  conditions  of  panel  18 54 

20.  Diagram  showing  temperature  conditions  of  panel  19 56 

21.  Diagram  showing  temperature  conditions  of  panel  20 58 

22.  Diagram  showing  temperature  conditions  of  panel  21 60 

23.  Diagram  showing  temperature  conditions  of  panel  22 62 

24 .  Diagram  showing  temperature  conditions  of  panel  23 65 

25.  Sketch  of  partition  tile  used  in  panel  24 66 

.  26.  Diagram  showing  temperature  conditions  of  panel  24 68 

27.  Diagram  showing  temperature  conditions  of  panel  25 71 

28.  Diagram  showing  temperature  conditions  of  panel  26 73 

29.  Diagram  showing  temperature  conditions  of  panel  27 76 

30.  Diagram  showing  temperature  conditions  of  panel  28 78 

31 .  Diagram  showing  temperature  conditions  of  panel  29 80 

32.  Diagram  showing  temperature  conditions  of  panel  30 84 


THE  FIRE-RESISTIVE 

BUILDING  MTERIALS 


By  KICHARD  L.  HUMPHREY. 


INTRODUCTION. 

SCOPE  AND  CHARACTER  OF  INVESTIGATIONS. 

This  bulletin  contains  the  results  of  tests  of  thirty  panels  of  vari- 
ous building  materials,  made  by  the  United  States  Geological  Survey 
with  a  furnace  in  the  Underwriters'  Laboratories,  Chicago,  111.,  to 
determine  the  effect  of  fire  and  subsequent  quenching  with  water 
on  mortar  building  blocks  made  of  river  and  slag  sands;  common, 
hydraulic-pressed,  and  sand-lime  brick;  gravel,  cinder,  limestone,  and 
granite  concrete;  glazed  building  and  partition  terra-cotta  tile;  and 
limestone,  sandstone,  granite,  and  marble  building  stone.  The  mor- 
tar building  blocks  and  the  concrete  were  made  in  the  structural- 
materials  testing  laboratories;  the  other  materials,  except  some  of 
the  common  brick,  were  obtained  in  the  open  market  at  Chicago,  111. 

The  investigations  herein  reported  are  a  preliminary  part  of  a 
comprehensive  series  undertaken  with  the  object  of  determining  the 
fire-resistive  properties  and  rates  of  heat  conductivity  of  various 
building  materials  and  the  comparative  efficiency  of  the  various 
methods  of  fireproofing.  These  investigations  have  the  further 
object  of  greatly  lessening  the  liability  of  loss  by  fire  in  government 
buildings  and  greatly  reducing  their  cost  through  more  efficient 
methods  of  construction.  While  the  tests  are  conducted  primarily 
for  the  purpose  of  obtaining  information  of  essential  value  to  the 
Government  it  is  believed  that  the  results  will  prove  to  be  of  much 
importance  to  the  general  public. 

The  materials  were  subjected  to  the  direct  application  of  heat  for 
two  hours  and  were  then,  except  in  five  panels,  immediately  quenched 
with  water.  Wherever  possible,  tests  were  made  to  determine  the 
compressive  strength  of  the  materials  after  this  treatment.  Tem- 
peratures were  observed  at  intervals,  and  the  behavior  of  the  mate- 
rials during  the  test  and  the  condition  of  their  surfaces  before  and 
after  the  heating  and  quenching  were  noted.  Photographs  of  the 
panels  were  taken  to  show  the  effects  of  the  tests. 

7 


8  FIRE  RESISTANCE  OF  VARIOUS  BUILDING  MATERIALS. 

The  tests  of  the  different  materials  were  carried  on  under  as  nearly 
identical  conditions  as  possible,  but  there  was  some  unavoidable 
variation  in  tji^  tfondit :\om*.  Tlie  furnace  had  never  been  used  for 
such  testi^ai^4- the  operators  were  inexperienced.  The  furnace  was 
in  almost  constant use  by  the  Underwriters'  Laboratories,  and  it  was 
necessary  to  arrange  the  tests  so  as  not  to  interfere  with  the  regular 
work  of  those  laboratories.  It  was  also  necessary  to  make  half  the 
tests  in  winter  and  the  other  half  in  summer,  and  many  of  the 
building  blocks  used  in  the  first  tests  were  subjected  to  freezing 
weather  just  prior  to  testing. 

Inasmuch  as  the  tests  herein  recorded  present  many  features  of 
considerable  importance,  it  has  been  deemed  highly  desirable  to  pub- 
lish a  detailed  account  of  them,  although  the  results  are  preliminary 
and  inconclusive,  and  are  presented  solely  for  the  purpose  of  making 
public  the  information  acquired.  They  should  not  therefore  be  used 
as  a  basis  for  drawing  conclusions,  but  merely  as  preliminary  data 
regarding  the  relative  fire-resistive  qualities  of  the  building  mate- 
rials tested. 

SYNOPSIS  OF  TESTS. 

The  conditions  under  which  these  tests  were  made  were  unusually 
severe  and  none  of  the  material  passed  perfectly.  The  temperatures 
used  would  hardly  be  reached  in  an  ordinary  fire.  It  was  recognized 
from  the  beginning  that  these  tests  would  not  be  comparable  with 
those  made  by  other  investigators.  The  relatively  few  tests  that 
have  been  made  of  the  fire-resistive  qualities  of  building  materials 
nearly  all  consisted  of  subjecting  floor  slabs  and  columns  to  the  heat 
of  a  wood  fire.  There  is  reason  to  believe  that  the  tests  herein 
described,  made  in  a  gas  furnace,  are  more  severe  than  the  tests 
made  with  a  wood  fire,  even  though  the  latter  show  higher  tempera- 
tures and  last  longer.  In  the  gas  furnace  the  flames  are  forced  by  a 
blast  of  air  against  the  panel  from  the  beginning  to  the  end  of  the 
test;  with  a  wood  fire  the  heat  fluctuates  and  falls  decidedly  when 
the  furnace  door  is  opened  and  fresh  fuel  is  added. 

Much  of  the  damage  done  to  the  building  materials  in  this  series 
of  tests  was  occasioned  by  internal  stresses,  the  gas  flame  heating 
one  face  of  the  test  pieces  much  more  rapidly  than  the  other  face. 
All  the  materials  tested,  including  the  hydraulic-pressed  brick, 
cracked  more  or  less.  The  concrete  cracked  least,  but  the  tests 
indicate  the  necessity  for  using  metal  reinforcement  in  concrete  walls 
to  distribute  the  effect  of  the  expansion. 

The  average  temperature  attained  by  the  faces  of  the  panels  10 
minutes  after  the  gas  was  lighted  was  about  324°  C.  (615.2°  F.), 
and  nearly  half  of  the  panels  had  been  subjected  to  freezing  weather 
just  prior  to  the  tests.  The  average  temperature  of  the  face  of  one 
panel  of  building  blocks  rose  from  0°  to  450°  C.  (32°  to  842°  F.)  in 


SYNOPSIS  OF  TESTS.  9 

the  first  10  minutes  of  firing,  while  that  of  another  panel  of  the  same 
material  ranged  from  22°  to .600°  C.  (71.6°  to  1,112°  F.)  during  the 
same  interval. 

Although  the  results  obtained  from  these  tests  will  not  be  crit- 
ically analyzed  in  this  bulletin,  a  few  of  the  more  important  features 
will  be  pointed  out. 

A  fact  brought  out  most  clearly  by  these  tests  is  the  low  heat- 
transmission  rate  of  Portland  cement  mortars  and  concretes.  This 
is  one  of  the  desirable  qualities  in  materials  intended  for  fireproofing 
purposes.  For  marking  the  cement  blocks  linen  tags  were  fastened 
by  wire  nails  to  the  ulterior  walls  at  the  time  of  molding.  Most  of 
these  tags  remained  in  place  during  the  test,  and  when  the  walls 
were  dismantled  the  tags  in  every  case  were  found  entirely  un- 
damaged. 

A  study  of  the  curves  at  the  bottom  of  the  diagrams  (figs.  1-12, 
14-24,  26-32)  will  show  the  comparatively  slight  increase  in  the 
temperatures  of  the  backs  of  the  blocks  during  the  test.  The  rise 
in  temperature  of  the  backs  of  the  building  blocks  made  of  river- 
sand  mortar  varied  from  25°  to  40°  C.  (77  °  to  104°  F.),  while  the  rise 
in  the  average  temperatures  of  the  faces  of  the  cement  blocks  ranged 
from  650°  to  900°  C.  (1,202°  to  1,652°  F.).  The  backs  of  the  mortar 
blocks,  made  of  slag  sand,  showed  a  rise  of  temperature  of  only  10°  C. 
( 30  °  F.) ,  while  the  faces  were  heated  up  to  800  °  C.  (1,472  °  F.) .  The 
low  rate  of  heat  conductivity  of  the  mortar  blocks  is  shown  by  the 
slowness  with  which  the  temperature  of  the  backs  of  the  panels  in- 
creased in  comparison  with  that  of  the  faces. 

An  average  of  all  the  tests  shows  that  about  90  per  cent  of  the 
maximum  temperatures  attained  by  the  faces  of  the  panels  were 
reached  in  one  hour,  while  in  the  case  of  the  mortar  blocks  the  in- 
crease in  temperature  of  the  backs  of  the  panels  in  one  hour  was  only 
about  20  per  cent  of  the  total  increase  in  the  two  hours.  Of  the  solid 
concrete  panels  the  cinder  concrete  showed  the  smallest  increase  in 
the  temperatures  of  the  backs  of  the  walls,  and  the  granite  concrete 
the  largest.  The  total  increase  in  the  temperatures  of  the  mortar 
panels  was  about  the  same  as  the  total  increase  in  the  temperatures 
of  the  backs  of  the  concrete,  but  the  increase  in  one  hour  was  some- 
what greater  in  the  case  of  concrete. 

The  damage  done  to  the  faces  of  the  mortar  and  concrete  panels 
would  probably  be  caused  at  a  temperature  about  half  that  of  the 
maximum  temperatures  reached,  owing  to  the  water  of  crystalliza- 
tion being  driven  from  the  mortar.  This  thin  layer  of  dehydrated 
mortar  may  have  formed  a  protective  coating  and  prevented  deep 
dehydration. 

The  backs  ol  the  brick  panels  also  showed  a  small  increase  in  tem- 
perature, but  the  natural  building  stones  and  the  tiles  proved  poorer 


10  FIRE  RESISTANCE   OF  VARIOUS  BUILDING  MATERIALS. 

nonconductors  of  heat.  The  temperature  of  the  back  of  a  panel 
composed  of  plastered  tiles  increased  to  128°  C.  (262.4°  F.). 

It  is  apparent  that  the  strength  of  the  webs  of  ordinary  hollow 
blocks  is  insufficient  to  resist  the  stresses  set  up  in  these  tests,  as  in 
many  tests  the  rapid  rise  in  temperature  and  the  subsequent  quench- 
ing of  one  of  the  faces  of  the  blocks  caused  the  webs  to  split.  It  was 
noticeable  that  the  richer  the  mortars  used  in  these  blocks  the  better 
they  withstood  the  tests.  The  amount  of  water  used  in  mixing  the 
mortars  had  a  similar  effect  on  the  fire-resistive  qualities;  the  mortars 
mixed  with  the  greatest  percentage  of  water  gave  the  best  results. 
This  may  be  clearly  seen  in  the  photographs  of  the  mortar  blocks 
after  the  water  treatment,  where  the  wetter,  richer  mixtures  often 
stand  out  apparently  undamaged,  in  contrast  with  the  spalled, 
damaged  faces  of  the  leaner,  drier  blocks. 

When  blocks  were  cracked  or  spalled  before  the  application  of 
the  water  the  damage  appeared  to  be  greater  in  the  dry  mixtures 
containing  the  greatest  percentage  of  sand,  and  it  was  further  ob- 
served during  the  fire  test  that  the  richer  mixtures  warmed  up  more 
slowly  than  the  others.  It  is  apparent  that  one  of  the  causes  of 
weakness  in  the  hollow  cement  building  blocks  under  these  fire  tests 
was  the  weakness  of  the  concrete,  a  too  dry  and  lean  mixture,  which, 
coupled  with  the  thinness  of  the  webs,  provided  insufficient  strength 
to  resist  the  stress  due  to  the  rapid  expansion  of  the  face.  It  is  quite 
possible,  as  was  shown  in  some  of  the  block  tests,  to  make  blocks 
which  will  pass  the  conditions  perfectly;  the  web  must  be  thick 
enough  to  give  the  necessary  strength. 

A  close  examination  of  the  blocks  that  had  not  been  quenched 
showed  that  the  1 : 2  blocks  were  seldom  affected  by  heat  to  a  greater 
depth  than  f  inch,  while  the  1 : 8  blocks  frequently  showed  the  effect 
of  the  fire  to  a  depth  of  2  inches.  The  blocks  made  of  slag  sand 
resisted  the  test  better  than  those  made  of  river  sand.  Before  the 
water  was  applied  to  the  slag-sand  blocks  no  damage  was  apparent, 
although  it  must  be  remembered  that  close  examination  of  the  panels 
between  the  fire  and  water  treatments  could  not  be  made  on  account 
of  the  heat.  After  the  quenching  the  faces  of  the  1:1J  slag-sand 
blocks  were  found  to  be  washed  away  to  a  depth  of  J  to  f  inch; 
and  those  of  the  1 :  2J  to  a  depth  of  ^  to  f  inch;  while  the  \  mixtures 
were  damaged  only  to  a  depth  of  J  to  f  inch.  The  surfaces  were  rough 
and  pitted,  but  hard.  In  only  one  block  was  the  web  cracked  through. 

There  was  great  difficulty  in  getting  accurate  results  from  strength 
tests  of  irregularly  shaped  fragments  from  the  backs  and  fronts  of 
blocks  after  the  fire  and  quenching  tests,  and  the  results  are  too  in- 
consistent to  be  conclusive.  The  average  compressive  strength  of  the 
faces  of  blocks  was  about  two-thirds  to  three-fourths  of  that  of  their 
backs,  varying  with  the  proportions  and  consistencies. 


SYNOPSIS  OF   TESTS.  11 

The  brick  panels  probably  withstood  the  tests  better  than  the 
other  materials.  The  common  brick  tested  comprised  unused  new 
Chicago  brick,  and  used  St.  Louis  brick.  Fifty  per  cent  of  the  new 
bricks  were  split,  while  60  to  70  per  cent  of  the  old  bricks  were  not 
damaged.  Lime  knots  seemed  to  be  responsible  for  most  of  the 
damage  to  the  new  bricks,  as  they  were  found  at  the  bottom  of  nearly 
all  the  cracks.  The  bricks  at  the  back  of  the  panels  were  entirely 
unaffected.  While  the  strength  tests  are  not  conclusive,  there  is 
apparently  little  difference  in  the  strength  of  these  bricks  before  and 
after  firing. 

The  hydraulic-pressed  brick  withstood  the  test  very  well.  No 
damage  was  apparent  after  the  firing  and  before  the  water  was 
applied,  and  although  a  number  of  the  bricks  cracked,  70  per  cent  of 
them  were  found  to  be  sound  after  quenching. 

The  sand-lime  brick  did  not  withstand  the  test  as  well  as  expected, 
but  the  sample  tested,  which  was  purchased  at  random,  appeared  to 
be  somewhat  below  average  quality. 

It  was  difficult  to  determine  whether  the  limestone,  granite,  gravel, 
or  cinder  concrete  sustained  the  least  damage.  The  faces  of  all  the 
panels  were  more  or  less  pitted  by  the  fire  and  washed  away  by  the 
stream  of  water.  The  test  was  unfair  to  the  cinder  concrete,  as  the 
cinder  was  very  poor,  containing  a  large  percentage  of  unburned 
coal;  however,  the  sample  selected  was  the  best  of  six  or  eight  inves- 
tigated in  St.  Louis.  During  the  fire  test  the  coal  ignited  and  left 
the  surface  of  the  concrete  very  rough  and  badly  pitted.  The  lime- 
stone aggregate  in  the  face  calcined,  and  the  granite  aggregate  split 
and  broke  away  from  the  surface  mortar.  The  granite  concrete 
probably  behaved  the  best.  The  damage  in  no  case  extended 
deeply,  probably  not  more  than  li  inches.  The  evidence  shows 
that  even  at  this  depth  the  temperature  was  comparatively  low. 
The  high  stresses  produced  in  the  panels  by  the  rapid  rise  of  tem- 
perature of  the  faces  while  the  backs  remained  cool  caused  cracks. 
On  taking  down  the  panels  the  blocks  of  concrete  were  found  to  be 
cracked  vertically  for  some  distance  back  from  the  face. 

The  serious  damage  to  the  various  natural  building  stones  pre- 
cludes any  comparison  among  them. 

The  tile  tested  was  bought  in  the  open  market,  and  in  one  panel 
was  taken  from  a  lot  of  material  about  to  be  erected  in  a  building. 
Large  percentages  of  the  faces  of  the  tiles  were  washed  away  by  the 
water,  and  the  material  composing  the  faces  became  soft  and  could 
be  easily  crumbled  in  the  fingers.  There  was  a  comparatively  rapid 
rise  in  the  temperature  of  the  back  of  the  panels.  The  plaster  on  the 
panel  of  partition  tile  fell  off  a  few  minutes  after  the  test  was  started. 

Heretofore  fire  tests  of  building  material  have  been  made  at  ran- 
dom and  scarcely  any  two  tests  are  comparable  one  with  the  Bother; 


12  FIEE  EESISTANCE   OF  VARIOUS   BUILDING   MATERIALS. 

it  is  therefore  hoped  that  the  next  series  of  tests  made  in  this  type  of 
furnace,  where  with  the  experience  gained  the  conditions  can  be 
more  closely  controlled,  will  lead  to  much  more  valuable  results. 

ACKNOWLEDGMENTS. 

These  investigations  were  made  possible  through  the  hearty  coop- 
eration and  proffer  of  facilities  by  the  Underwriters'  Laboratories,  Inc., 
located  at  382  Ohio  street,  Chicago,  111.  The  courtesies  and  cooper- 
ation of  Prof.  R.  Burnham,  of  the  Armour  Institute,  in  whose  labo- 
ratories the  compression  tests  on  the  treated  test  pieces  were  made, 
are  hereby  acknowledged. 

The  building-block  machines  used  in  making  the  mortar  blocks 
were  selected  by  a  special  committee  of  the  United  Concrete  Block 
Machinery  Manufacturers'  Association;  the  machines  represented 
different  types  and  were  loaned  through  the  courtesy  and  coopera- 
tion of  the  following  companies : 

American  Hydraulic  Stone  Company,  Denver,  Colo. 
Cement  Machinery  Company,  Jackson,  Mich. 
Dykema  Company,  Grand  Rapids,  Mich. 
Miracle  Pressed  Stone  Company,  Minneapolis,  Minn. 
P.  B.  Miles  Manufacturing  Company,  Jackson,  Mich. 

The  cement  used  in  the  building  blocks  and  the  concrete  was  a 
mixture  of  a  number  of  brands  of  cement  which  were  donated  by  the 
following  companies: 

Atlas  Portland  Cement  Company,  Hannibal,  Mo. 
Edison  Portland  Cement  Company,  New  Village,  N.  J. 
lola  Portland  Cement  Company,  lola,  Kans. 
Lehigh  Portland  Cement  Company,  Mitchell,  Ind. 
Omega  Portland  Cement  Company,  Jonesville,  Mich. 
St.  Louis  Portland  Cement  Company,  St.  Louis,  Mo. 
Virginia  Portland  Cement  Company,  Fordwick,  Va. 

The  sand  referred  to  as  "Meramec  River  sand,"  used  in  the  building 
blocks  and  concrete,  was  contributed  by  the  Union  Sand  and  Material 
Company,  of  St.  Louis,  Mo.  The  slag  sand  used  in  a  few  of  the  blocks 
was  contributed  by  the  Carnegie  Steel  Company  of  Pittsburg,  Pa. 

SOURCE  OF  MATERIALS   TESTED. 

Common  brick. — Two  samples  of  common  brick  were  tested,  one  a 
Chicago  brick  selected  in  the  yard  of  the  makers,  and  the  other  a 
St.  Louis  brick  taken  from  the  foundation  of  a  dismantled  briquetting 
machine  of  the  Government's  fuel-testing  plant,  Forest  Park,  St. 
Louis,  Mo. 

Hydraulic-pressed  brick. — The  hydraulic-pressed  brick  was  manu- 
factured in  Indiana  and  taken  from  a  pile  being  used  in  the  construc- 
tion of  a  building  in  Chicago. 


SOURCE   OF   MATERIALS   TESTED.  13 

Sand-lime  brick. — The  sand-lime  brick  was  manufactured  in  Indi- 
ana and  taken  from  a  stock  pile  in  Chicago. 

Mortar  building  Hocks. — The  building  blocks  were  molded  at  the 
Government's  structural-materials  testing  laboratories,  St.  Louis, 
Mo.,  on  five  different  designs  of  machines  representing  distinct  types. 

The  blocks  in  tests  1  to  10,  inclusive,  were  made  of  sand  dredged 
from  Meramec  River  at  Drake,  Mo.,  and  "typical  Portland "  cement. 
They  were  made  in  three  different  consistencies,  damp,  medium,  and 
wet ;  and  in  three  proportions,  1 :  2,  1 :  4,  and  1:8.  An  equal  number 
of  each  consistency  made  in  the  three  proportions  were  tested  in  the 
same  panel. 

The  Meramec  River  sand  was  of  average  quality  and  free  from 
silt,  its  grading  being  quite  uniform.  The  results  of  a  large  number 
of  tests  with  this  sand  and  a  description  of  the  "typical  Portland" 
cement,  which  is  a  thorough  mixture  of  a  number  of  brands,  are  given 
in  Bulletin  331.° 

The  blocks  in  panel  14  were  of  "typical  Portland"  cement  and 
slag  sand,  made  of  medium  consistency  and  in  the  proportions  of 
l:li,  1:2J,  and  1:4. 

In  panels  15  and  16  were  tested  two  parallel  series  of  Meramec 
sand  blocks  of  medium  consistency,  mixed  in  proportions  of  1:2,1:4, 
and  1:8;  those  in  panel  15  were  cured  in  the  moist  room,  while  those 
in  panel  16  were  cured  hi  dry  air.  These  last  two  sets  of  blocks  and 
the  slag-sand  blocks  were  made  on  the  single-air-space  type  of 
machine  only. 

Terra-cotta  tile. — Two  kinds  of  terra-cotta  tile  were  tested,  one  a 
hollow  glazed  building  tile,  8  by  8  by  16  inches,  having  a  4-inch  web, 
with  four  core  holes  running  throughout  its  length,  and  the  other  a 
partition  tile,  5  by  12  by  12  inches,  having  a  f-inch  web  and  three 
core  holes.  The  former  tiles  were  taken  from  a  stock  pile  in  Chi- 
cago ;  the  latter  were  obtained  by  purchase  from  a  lot  of  material  that 
had  been  delivered  by  the  manufacturers  at  the  site  of  a  building  in 
course  of  construction  in  which  they  were  being  used  for  fireproofing. 

Concrete. — The  concretes  tested  were  pieces  of  broken  beams  that 
had  been  tested  in  the  Government's  structural-materials  testing 
laboratories  at  St.  Louis,  Mo.  The  pieces  were  8  by  11  inches  in 
cross  section  and  of  various  lengths.  They  were  fired  with  the 
11-inch  face  exposed.  In  making  the  concretes  four  distinct  types 
of  aggregate  had  been  used — limestone,  granite,  gravel,  and  cinder. 
The  aggregate  was  sized  to  pass  a  1-inch  screen  and  be  retained  on  a 
|-inch  screen.  The  concretes  had  been  mixed  in  proportions  of  1  of 
cement,  2  of  Meramec  River  sand,  and  4  of  aggregate,  and  were  of 
medium  consistency. 

a  Humphrey,  Richard  L.,  and  Jordan,  William,  jr.,  Portland  cement  mortars  and  their  constituent 
materials:  Bull.  U.S.  Geol.  Survey  No.  331, 1908. 


14  FIRE  RESISTANCE   OF  VARIOUS  BUILDING  MATERIALS. 

The  limestone  was  obtained  in  St.  Louis,  Mo.  The  gravel  was 
dredged  from  Meramec  River  at  Drake,  Mo. ;  it  was  clean,  hard,  and 
flinty.  The  granite  was  the  red  granite  from  Graniteville,  Mo. 
The  cinder,  obtained  from  a  large  power  house  in  St.  ,Louis,  was 
poor,  containing  24.5  per  cent  of  combustible  material. 

Building  stone. — The  four  kinds  of  building  stone  tested — sand- 
stone, limestone,  marble,  and  granite — were  obtained  by  purchase 
in  the  open  market  in  Chicago,  111.  There  were  two  kinds  of  lime- 
stone, one  the  Bedford  limestone  (Carboniferous)  from  Bedford. 
Ind.,  and  the  other  a  Niagaran  magnesian  limestone  from  Joliet,  111, 
The  sandstone  was  from  the  Carboniferous  at  Cleveland,  Ohio.  The 
marble  was  from  Georgia,  and  the  granite  from  Thousand  Islands, 
Canada,  except  one  sample  of  a  granite  from  Maine,  which  was 
reported  to  be  such  as  was  used  in  the  construction  of  the  post-office 
building  in  Chicago,  111. 

APPARATUS. 

Furnace. — The  apparatus  in  which  these  tests  were  made  is  similar 
to  that  generally  used  in  determining  the  fire-resistive  qualities  of 
fire  doors  and  windows.  It  comprises  a  gas  furnace  with  a  movable 
steel-frame  fire-brick  wall  or  door  14  inches  thick  (A,  PL  I,  A)  that 
shuts  off  the  furnace  from  a  radiation  chamber.  The  distance 
between  the  permanent  back  wall  of  the  furnace  and  the  movable 
wall  is  13J  inches.  The  movable  wall  is  hung  from  the  lower  flange 
of  an  I  beam  by  rollers  and  is  easily  moved  out  of  position  by  a  weight 
(B,  PL  I,  A)  attached  to  a  wire  cable.  The  wall  has  an  arched 
opening  6  feet  wide  and  9  feet  high.  The  material  to  be  tested  is 
built  up  in  this  opening  as  a  panel  (PL  I,  B). 

The  stationary  back  wall  of  the  furnace  contains  holes  through 
which  air  is  admitted  to  control  the  temperature.  Back  of  this  wall 
are  piping  and  valves  for  the  control  of  the  air  and  gas  supply  (PL  I, 
A) .  The  air  pressure  for  the  flame  is  maintained  by  a  motor-driven 
fan  (D,  PL  I,  .A).  Gas  enters  the  fire  chamber  at  the  bottom  through 
burners  which  are  below  the  level  of  the  floor  and  do  not  show  in  the 
accompanying  view  of  the  interior  of  the  furnace  (PL  II,  A).  The 
piping  against  the  face  of  the  wall  in  this  view  is  a  water  pyrometer. 

When  a  panel  is  ready  for  testing  it  is  drawn  into  position  in  front 
of  the  main  wall  by  a  hand  winch  (C,  PL  I,  A)  and  held  there  by  a 
latch.  The  opening  around  the  edges  is  sealed  by  fire  clay.  Then 
the  gas  is  turned  on  and  lighted  by  a  torch  inserted  through  a  small 
door  (E,  PL  I,  A).  The  observer  can  watch  the  behavior  of  the 
furnace  and  the  materials  under  test  through  three  small  mica  peep 
holes  in  the  sides  of  the  furnace  (F,  PL  I,  A). 

At  the  end  of  the  heat  treatment  the  latch  is  released  and  the 
weight  at  once  draws  the  wall  from  the  furnace.  In  a  regular  test  the 
material  in  the  panel  is  immediately  quenched  with  water  from  a  nozzle. 


U.  S.  GEOLOGICAL  SURVEY 


BULLETIN  370   PLATE 


A.     WEST  VIEW  OF  FURNACE,  SHOWING    RADIATION  CHAMBER  AND  PANEL  (A)   IN    POSITION 

FOR  QUENCHING. 


F>.     SOUTHEAST  VIEW  OF  FURNACE,  SHOWING  FIRE  CHAMBER  AND   PANEL  BUILT  UP  IN 

MOVABLE  WALL. 


APPARATUS.  15 

Throughout  this  bulletin  the  side  of  the  panel  subjected  to  the 
heat  of  the  furnace  is  referred  to  as  the  face  of  the  panel;  the  opposite 
side,  which  is  exposed  to  the  air,  is  referred  to  as  the  back  of  the 
panel. 

Apparatus  for  measuring  temperature. — The  temperatures  of  the 
furnace  and  of  the  face  of  the  panel  during  the  tests  herein  described 
were  determined  by  means  of  platinum  and  iridium  thermocouples; 
the  temperatures  of  the  back  of  the  panel  were  measured  by  means 
of  mercury  thermometers.  In  addition,  the  average  temperature  of 
the  interior  of  the  furnace  was  found  by  the  water  pyrometer. 

Four  thermocouples  were  inserted  through  the  back  wall  into  the 
furnace  chamber,  each  extending  through  a  steeL  tube  3^  inches 
long  and  f  inch  in  diameter.  Smaller  clay  tubing  surrounded  the 
couples  and  protected  them  from  the  steel  tubing.  The  couples 
projected  into  the  fire  chamber  about  4|  inches,  but  only  the  point 
of  each  couple,  about  f  inch,  was  exposed,  the  rest  of  the  4^  inches 
being  protected  from  the  fire  by  a  cone  of  fire  clay. 

The  temperatures  of  the  face  of  the  panel  were  measured  by  six 
thermocouples  incased  in  clay  tubing  that  passed  through  f-inch 
steel  tubing  laid  in  the  mortar  joints.  The  ends  of  the  tubes  extended 
within  ^  inch  of  the  face  of  the  panel,  and  the  points  of  the  couples 
were  placed  about  TV  inch  back  from  the  face  and  surrounded  with 
a  thin  coating  of  fire  clay.  To  the  free  ends  of  the  couples  were 
soldered  pieces  of  copper  wire  about  3  feet  long;  cold  junction  bottles 
were  used  to  keep  the  soldered  junctions  of  the  ends  of  the  couples 
and  the  copper  wire  at  a  constant  temperature.  These  bottles  had 
large  mouths  closed  by  corks  and  were  filled  with  water  and  sur- 
rounded with  magnesia  pipe  covering.  Through  each  cork  were 
inserted  two  test  tubes,  about  6  inches  long,  and  a  thermometer. 
Each  test  tube  held  a  junction.  From  the  bottles  the  copper  wires 
led  through  a  switch  to  an  Englehardt  galvanometer.  Prior  to  the 
tests  the  thermocouples  were  calibrated  against  this  instrument. 

The  general  arrangement  of  the  thermocouples,  cold  junction 
bottles,  switch,  and  galvanometer  is  shown  in  Plate  IV.  Plate  II,  B, 
shows  the  thermometers  and  cold  junction  bottles  in  position  at  the 
back  of  a  panel. 

The  temperatures  of  the  back  of  each  panel,  taken  to  determine 
the  rate  of  heat  transmission,  were  measured  by  thermometers  held 
in  contact  with  the  surface  of  the  panel  by  small  lumps  of  fire  clay. 

The  temperatures  recorded  by  each  couple,  the  water  pyrometer, 
the  thermometers  against  the  back  of  the  panels,  and  the  thermome- 
ters in  the  junction  bottles  were  platted  after  each  test  (figs.  1  to  12, 
14  to  24,  26  to  32).  The  curve  drawn  through  the  plotted  points 
represents  the  average  in  each  test. 


16  FIRE  RESISTANCE   OF  VARIOUS   BUILDING   MATERIALS. 

The  Weather  Bureau  records  of  the  minimum  and  maximum  air 
temperatures,  the  humidity,  and  the  wind  direction  for  the  particular 
day  of  each  test  are  given  below  the  diagrams  showing  the  above 
curves. 

PREPARATION  OF  MATERIALS  TESTED. 

Preparation  of  building  blocks. — The  methods  used  in  molding 
and  curing  the  concrete  building  blocks  at  the  Government's  struc- 
tural-materials testing  laboratories  are  described  in  Bulletin  329  .a 
The  proportions,  while  stated  in  parts  by  volume,  were  actually  by 
weight,  allowance  being  made  for  the  percentage  of  moisture  in  the 
sand,  which  was  determined  as  used.  The  mixing  was  done  in  a  J 
cubic  yard  Chicago  cubical  concrete  mixer,  the  sand  and  cement  being 
thoroughly  mixed  before  the  water  was  added.  The  three  consist- 
encies, indicated  by  the  terms  "damp,"  "  medium,"  and  "wet,"  are 
defined  as  follows:  (1)  In  damp  consistency  the  per  cent  of  water 
used  gives  the  driest  mixture  which  can  be  handled  in  all  five  types 
of  block  machines;  (2)  medium  consistency  is  halfway  between 
damp  and  wet  consistencies;  (3)  in  wet  consistency  the  percentage 
of  water  used  gives  the  wettest  mixture  which  can  be  handled. 

All  the  blocks,  with  the  exception  of  those  made  on  an  American 
Hydraulic  Stone  Company  machine,  a  pressure  machine,  were  hand 
tamped,  and  great  care  was  taken  to  tamp  them  all  in  the  same  man- 
ner and  for  the  same  length  of  time.  The  blocks  in  any  one  batch 
were  not  permitted  to  vary  more  than  1  per  cent  in  weight.  They 
remained  on  the  pallets  60  hours,  and  then,  with  the  exception  of  a 
set  left  in  the  air  of  the  laboratory,  were  placed  in  a  moist  room, 
where  they  were  sprinkled  at  8-hour  intervals. 

For  transportation  to  Chicago  the  blocks  were  packed  in  straw  in 
a  refrigerator  car,  and  the  car  was  filled  with  live  steam  and  sealed. 
On  reaching  the  Underwriters'  Laboratories  they  were  piled  in  a 
warm,  dry  room  until  tested.  The  length  of  time  that  each  set  of 
blocks  remained  in  the  moist  room,  in  the  car,  and  at  the  Under- 
writers' Laboratories  is  noted  in  the  description  of  each  test. 

The  blocks  were  built  up  in  the  panel  without  breaking  the  joints, 
in  order  to  obviate  the  necessity  of  cutting  any  of  the  blocks. 

Preparation  of  concrete. — The  concrete,  consisting  of  portions  of 
unreinforced  beams  which  had  been  tested,  was  stored  in  a  moist 
room  and  sprinkled  at  8-hour  intervals,  both  before  and  after  it  was 
tested.  For  a  description  of  the  method  of  mixing  and  molding  the 
concrete,  see  Bulletin  329. 

Preparation  of  building  stone,  brick,  and  tile. — These  building 
materials  were  placed  in  the  panel,  as  nearly  as  space  would  allow,  in 
exactly  the  same  way  that  they  would  be  laid  in  the  wall  of  a  building. 

a  Humphrey,  Richard  L.,  Organization,  equipment,  and  operation  of  the  structural-materials  testing 
laboratories  at  St.  Louis,  Mo.:  Bull.  U.  S.  Geol.  Survey  No.  329,  1908. 


U.    S.   GEOLOGICAL  SURVEY 


BULLETIN    370      PLATE  II 


A.    VIEW  OF  FURNACE  WITH  PANEL  REMOVED,  SHOWING  SECONDARY 
AIR  INLETS  AND  WATER  PYROMETER. 


B.    VIEW  OF  BACK  OF  PANEL,  SHOWING  THE  COLD  JUNCTION  BOTTLES  AND  THERMOMETERS 

IN  PLACE. 


'P  '      '      "      r-'      ' 

•  v  :*-'5*..: 


-K- *= -=&—  --:= 9 


FIRE   RESISTANCE   OF  VARIOUS  BUILDING   MATERIALS.  17 

METHOD   OF   CONDUCTING   TESTS. 

Fire  tests. — The  test  wall  with  the  panel  filled  with  the  material  to 
be  tested  was  allowed  to  dry  out  for  several  hours,  and  was  then 
drawn  into  position  by  means  of  the  winch,  and  latched.  The  open- 
ings around  this  wall  and  the  furnace  were  sealed  up  with  fire  clay. 
The  pyrometers  were  then  placed  in  position  in  the  joints  and  the 
thermometers  were  attached  to  the  back  of  the  panel,  as  shown  in 
Plate  II,  B.  The  wires  from  each  thermocouple  (PL  IV)  led  to  a 
10-point  switch,  connected  with  the  galvanometer,  placed  on  a  table 
a  short  distance  back  of  the  panel.  One  of  the  operators,  seated  at 
this  table,  recorded  the  readings  of  the  galvanometer  on  each  of  the 
ten  couples  at  10-minute  intervals;  the  other  operator  regulated  the 
supply  of  gas  and  air,  read  the  thermometers,  and  noted  the  be- 
havior of  the  furnace  and  of  the  panel  under  test. 

An  effort  was  made  to  obtain  the  maximum  temperature  (1,700°  F.) 
within  one-half  hour  after  starting  the  test,  and  to  maintain  this 
temperature  as  nearly  constant  as  possible  throughout  the  succeed- 
ing time.  At  the  end  of  2  hours  the  thermometers,  thermo-couples, 
and  cold  junction  bottles  were  quickly  removed,  the  gas  turned  off, 
and  the  latch  raised,  allowing  the  wall  to  be  pulled  out  by  means  of 
the  counter  weight. 

Quenching  tests. — As  soon  as  the  wall  was  free  from  the  furnace  the 
face  of  the  panel  which  had  been  exposed  to  the  heat  was  quenched  by 
a  stream  of  water.  The  water  was  applied  for  5  minutes  at  a  pressure 
of  50  pounds  to  the  square  inch  through  a  f-inch  nozzle  held  20  feet 
from  the  face  of  the  panel  (PL  III).  The  average  interval  between 
shutting  off  the  gas  and  applying  the  water  was  1  minute.  Photo- 
graphs were  taken  of  the  face  and  back  of  the  panel  both  before  and 
after  the  test. 

Strength  tests. — As  soon  as  the  panel  had  become  cool  enough  to 
permit  handling  the  test  pieces,  it  was  dismantled  and  such  test 
pieces  as  could  be  obtained  were  hauled  to  the  Armour  Institute, 
Chicago,  where  they  were  tested  for  compressive  strength  by  a 
200,000-pound  Olsen  testing  machine.  The  results  of  the  strength 
tests  are  given  in  Tables  1  to  10,  inclusive. 

RESULTS   OF  TESTS. 

PANEL  1  (Mortar  Building  Blocks). 

Material. — Panel  1  was  composed  of  27  "typical  Portland"  cement 
and  Meramec  River  sand  one-piece  double-air-space  blocks,  laid  up  in 
fire  clay  without  breaking  joints.  There  were  three  blocks  each,  of 
1:2,  1:4,  and  1 : 8  mixtures,  damp,  medium,  and  wet.  The  blocks  had 
been  stored  in  a  moist  room  and  sprinkled  twice  daily  at  the  St.  Louis 
laboratories  52  days,  packed  in  straw  in  a  refrigerator  car  which  was 
73087— Bull.  370—09 2 


18 


FIKE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


fOOO 
9OO 


000 


T/ME  //V 


FIGURE  1.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  1.  Temper- 
ature: Maximum,  34°;  minimum,  28°;  mean,  31°.  Relative  humidity:  7  a.  in.,  95;  7  p.  m.,  80.  Direc- 
tion of  prevailing  wind,  east. 


KESULTS   OF    TESTS.  19 

en  route  to  Chicago  3  days,  stored  in  a  warm  room  in  the  Underwriters' 
Laboratories  8  days,  and  were  finally  tested  at  the  age  of  63  days.  The 
panel  was  laid  up  in  freezing  weather. 

Test. — Firing  started  at  2:10  p.  m.  January  17,  1907,  and  con- 
tinued for  2  hours  3J  minutes.  The  panel  was  cooled  in  air  after  the 
test  without  the  application  of  water. 

In  38  minutes  steam  appeared  through  the  joints  at  the  top  of 
the  panel.  At  the  expiration  of  55  minutes  the  blocks  began  to 
sweat,  particularly  those  of  1 : 2  and  1 :  4  proportions.  The  top  of  the 
panel  was  warmer  than  the  middle  and  the  lower  portions,  especially 
the  1 : 8  blocks.  The  back  of  the  1 : 8  blocks  felt  warmer  than  the  backs 
of  those  of  the  richer  mixtures. 

The  variations  of  temperature  of  the  furnace,  determined  by  the 
water  pyrometer  and  the  thermocouples,  of  the  temperature  of  the 
face  and  back  of  the  panel,  and  of  the  cold  junction  bottles  are  shown 
in  figure  1 . 

Results. — Plate  V,  A,  shows  the  face  of  the  panel  after  cooling. 
Vertical  cracks  along  the  webs,  clearly  shown  in  the  plate,  developed 
in  each  row  of  blocks.  There  were  no  signs  of  spalling.  The  surface  of 
the  1 : 8  blocks  could  be  rubbed  away  easily  with  the  finger,  that  of 
the  1 : 2  blocks  with  difficulty.  The  faces  of  the  1 : 2  blocks  were  dis- 
colored by  the  heat  to  a  depth  of  J  to  f  inch,  that  of  the  1 : 4  to  a 
depth  of  about  |  to  1  inch,  and  that  of  the  1 : 8  to  a  depth  of  about  1  % 
to  2  inches.  The  damp,  medium,  and  wet  consistency  blocks  showed 
no  difference  in  appearance.  The  back  of  the  panel  showed  no  ap- 
parent change. 

On  dismantling  the  panel  it  was  found  that  every  block  had 
cracked  across  the  web  and  split  out  at  the  face,  leaving  the  inner  web 
intact.  All  consistencies  and  proportions  failed  in  about  the  same 
manner. 

The  results  of  the  compression  tests  on  the  fragments  of  blocks 
after  the  fire  tests  are  given  in  Table  1, 

PANEL  2  (Mortar  Building  Blocks). 

Material. — Panel  2,  one-piece  single-air-space  blocks,  was  made 
up  the  same  as  panel  1,  but  had  been  in  the  St.  Louis  laboratories  one 
day  less  and  in  Chicago  one  day  more. 

Test. — Firing  started  at  3.11  p.  m.  January  18,  1907,  and  con- 
tinued for  2  hours  1  minute.  The  panel  was  cooled  in  air  without 
application  of  water. 

In  30  or  40  minutes  after  starting  steam  began  to  come  through 
the  mortar  joints.  At  60  minutes  the  back  of  the  wall  began  to 
sweat  and  to  get  warm  to  the  hand,  getting  warmer  faster  at  the  top 


20 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


/MO 


900 


600 


-MO 


300 
200 
/M 


FACE.  OF  PANEL 


700 


I- 


FURNACE 


kj   /M 

^  /000 
\3M 

B 


700 

600 


WATER   PYROMETER 


300 


/Off 


BACK   OF  PANEL 


9       i 


FIGURE  2.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  2.  Tem- 
perature: Maximum,  37°;  minimum,  34°;  mean,  36°.  Relative  humidity:  7  a.  m.,  91;  7  p.  m.,  94.  Direc- 
tion of  prevailing  wind,  southeast. 


RESULTS   OF   TESTS.  21 

than  at  the  bottom.  The  1 : 2  blocks  warmed  more  slowly  than  those 
of  leaner  proportions. 

Curves  showing  the  variations  of  the  temperature  are  given  in 
figure  2. 

Results. — When  removed  from  the  furnace  no  cracks  were  visible, 
but  while  cooling  small  hair  cracks  developed  all  over  the  blocks. 
On  the  1 : 2  blocks,  especially  the  wet  mixtures,  these  cracks  were 
very  fine,  but  on  the  1 : 4  and  1 : 8  blocks  they  were  coarser  and  more 
extensive.  The  surfaces  appeared  smooth,  but  could  be  easily 
scratched.  Plate  V,  B,  shows  the  face  of  the  panel  after  cooling  in 
air.  The  hair  cracks  are  too  small  to  be  visible  in  the  photographs. 
On  taking  the  panel  down  all  the  blocks  were  found  to  have  cracked 
across  the  web  nearest  the  fired  side.  To  remove  the  detached  fired 
face  without  cracking  it  vertically  was  difficult. 

Table  2  gives  the  results  of  the  strength  tests  on  fragments  of  the 
fired  blocks,  one  column  giving  the  strength  of  the  face  of  the  block 
exposed  to  the  fire  and  another  the  strength  of  the  back  of  the  blocks. 
The  table  shows  conclusively  the  loss  in  strength  of  the  fired  face. 

PANEL  3  (Mortar  Building  Blocks). 

Material. — Panel  3  consisted  of  one-piece  double-air-space  blocks 
exactly  like  those  in  panel  1,  except  that  they  had  been  made  four 
days  later  and  therefore  were  four  days  less  time  in  St.  Louis,  and 
the  same  length  of  time  longer  in  Chicago.  The  panel  was  laid  up  in 
the  afternoon  of  January-  19,  1907,  during  a  rain  storm.  The  tem- 
perature on  January  20  was  below  freezing  all  day. 

Test. — Firing  started  at  3  p.  m.  January  21,  and  continued  for  2 
hours.  Water  at  a  temperature  of  36°  F.  was  applied  to  the  panel 
for  5  minutes,  but  not  until  19  minutes  after  the  gas  was  turned  off, 
as  the  door  stuck  in  the  furnace. 

From  3  to  5  minutes  after  starting  the  test  considerable  snapping 
was  audible,  but  no  cracks  became  visible.  In  10  minutes  a  1 :8  dry 
block  opposite  an  air  jet  spalled  at  one  corner,  and  5  minutes  later 
the  spalling  continued  across  the  block  and  the  lower  edge  became 
loose.  At  20  minutes  another  1:8  dry  block  spalled  along  the  lower 
edge  and  the  right-hand  side.  This  spalling  extended  up  3  to  4  inches, 
though  it  did  not  penetrate  more  than  %  to  }  inch.  At  70  minutes 
the  blocks  began  to  sweat  and  steam  came  from  the  joints. 

Curves  showing  the  variations  of  the  temperature  throughout  the 
test  are  given  in  figure  3. 

Results.'—  Vertical  cracks  on  each  side  of  the  center  webs  showed 
plainly  before  the  application  of  the  water.  Plate  VI,  A,  shows  the 
face  and  Plate  VI,  B,  the  back  of  the  panel  after  quenching.  These 
views  show  clearly  how  different  blocks  met  the  tests,  the  richer  wet 


22 


FIKE   RESISTANCE    OF   VAKIOUS   BUILDING   MATERIALS. 


T/rt£  //V  MMUTES 

FIGURE  3.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  3.  Tem- 
perature: Maximum,  27°;  minimum,  4°;  mean,  16°.  Relative  humidity:  7  a._m.,86;  7  p.  m.,83.  Direc- 
tion of  prevailing  wind,  southeast. 


RESULTS   OF    TESTS.  23 

blocks  withstanding  it  much  better  than  the  lean  damp  blocks.  A 
peculiarity  of  the  behavior  of  this  type  of  block  during  the  test  may 
be  seen  in  Plate  VI,  B.  The  end  webs  split  away  from  and  parallel 
to  the  face  of  the  blocks,  but  the  middle  web  remained  intact  and 
the  face  split  away  from  it  at  each  side,  leaving  from  1  to  4  inches 
of  the  face  in  place. 

Table  3  gives  the  compressive  strength  of  the  fragments. 

PANEL  4  (Mortar  Building  Blocks). 

Material, — Panel  4  was  made  of  one-piece  single-air-space  blocks 
exactly  like  those  in  panel  2,  except  that  they  were  made  and  tested 
5  days  later,  and  therefore  remained  in  St.  Louis  5  days  less  time  and 
in  Chicago  5  days  longer. 

Test. — Firing  started  at  2.36  p.  m.  January  23,  1907,  and  continued 
for  2  hours  and  1  minute.  Water  at  a  temperature  of  36°  F.  was 
applied  for  5  minutes  and  20  seconds,  beginning  within  1  minute 
after  the  gas  was  turned  off. 

In  20  minutes  a  block  on  the  left-hand  side,  third  row  from  the  bot- 
tom, opposite  an  air  jet,  bulged  out  at  the  center  about  J  inch  and 
cracked  horizontally  at  about  the  center.  At  26  minutes  a  block  on 
the  right-hand  side  in  the  sixth  row  bulged  and  cracked  vertically. 
At  32  minutes  the  block  on  the  left-hand  side  in  the  third  row 
bulged  still  more,  and  2  minutes  later  the  face  fell  off.  At  37  min- 
utes the  center  block  in  the  third  row  opposite  an  air  jet  bulged 
about  J  inch.  At  80  minutes  the  blocks  began  to  sweat  and  steam 
came  through  the  joints. 

The  curves  showing  the  variations  of  the  temperature  throughout 
the  test  are  given  in  figure  4. 

Results. — Plate  VII  shows  the  face  and  back  after  firing  and 
quenching.  Plate  VIII,  At  shows  the  condition  of  the  blocks  during 
dismantling.  When  the  panel  was  withdrawn  from  the  fire  the  sur- 
faces of  the  blocks  were  smooth  except  where  the  blocks  had  spalled. 
Xo  cracks  were  visible.  During  the  application  of  the  water  all  the 
blocks  spalled,  but,  as  may  be  seen  from  the  plates,  this  spalling  was 
most  severe  on  the  lean  damp  blocks.  The  fourth  and  seventh  rows 
from  the  bottom  in  Plate  VII,  A,  are  1:2  blocks;  the  rows  next 
beneath  are  1 : 8  blocks.  The  difference  in  the  damp,  medium,  and  wet 
consistency  blocks  in  the  two  rows  is  perceptible.  The  1 : 8  and  1 : 4 
proportions  were  badly  spalled  and  washed  away. 

On  dismantling  the  panel  all  the  blocks  were  found  to  be  split 
across  the  webs.  These  cracks  were  along  the  fired  face  except  in 
two  or  three  cases,  where  the  webs  split  away  from  both  the  face  and 
the  back.  A  piece  of  wood  left  in  the  interior  of  one  of  the  blocks, 
was  slightly  scorched,  but  not  at  all  charred. 

The  strengths  of  the  fragments  are  given  in  Table  4. 


24 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


S  S  * 


FIGURE  4.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  4.  Tem- 
perature: Maximum,  22°;  minimum,  G°;  mean,  14°.  Relative  humidity:  7  a.  in., 83;  7  p.  m.,  85.  Direc- 
tion of  prevailing  wind,  northwest. 


RESULTS   OF   TESTS.  25 

PANEL  5  (Mortar  Building  Blocks). 

Materials. — Panel  5  consists  of  one-piece  single-air-space  blocks 
made  in  the  same  way  and  of  the  same  proportions  and  consistencies 
as  those  previously  tested.  They  were  stored  in  a  moist  room  at 
St.  Louis  45  days  and  at  Chicago  16  days,  and  were  tested  at  the  age 
of  64  days.  The  panel  was  laid  up  in  freezing  weather  and  was  frozen 
when  the  test  began. 

Test. — Fire  started  10.14  a.  m.  January  25,  1907,  and  continued 
for  2  hours  and  5  minutes,  after  which  the  panel  was  quenched  with 
water  at  a  temperature  of  36°  F.,  applied  for  5  minutes.  The  fire 
worked  badly,  the  panel  at  the  top  not  heating  up  as  well  as  desired. 
There  was  considerable  snapping  and  cracking  at  the  start,  which 
stopped  as  soon  as  the  panel  became  well  heated. 

In  25  minutes  a  block  on  the  right-hand  side,  third  row,  spalled 
slightly  at  the  center  and  showed  some  horizontal  cracks.  During 
the  remainder  of  the  test  the  panel  showed  no  change. 

Curves  showing  the  variations  of  the  temperature  throughout  the 
test  are  given  in  figure  5. 

Results. — As  the  top  of  the  furnace  did  not  heat  up  properly,  the 
blocks  in  the  upper  part  of  the  panel  were  not  affected  as  much  as 
those  in  the  lower  and  middle  portions.  Plate  VIII,  B,  shows  the 
face  of  the  panel  after  the  test,  Plate  IX,  A,  the  back  of  the  panel 
after  the  test,  and  Plate  IX,  B,  the  panel  during  dismantling.  The 
surfaces  of  the  blocks  were  badly  pitted,  but  no  cracks  appeared 
except  in  the  1:8  damp  blocks.  The  1:4  blocks  spalled  badly;  the 
1:2  blocks  slightly.  The  difference  in  the  behavior  of  the  rich  wet 
blocks  and  the  lean  damp  blocks  can  clearly  be  seen  in  Plate  VIII,  B. 

On  dismantling  the  panel  the  blocks  were  found  to  be  all  cracked 
along  the  webs,  so  that  the  faces  could  be  removed  without  disturbing 
the  backs.  It  was  also  found  that  the  faces  of  the  blocks  were 
cracked  vertically,  though  the  cracks  did  not  show  badly;  yet  few 
of  the  faces  could  be  removed  in  one  piece.  Most  of  the  webs 
cracked  close  to  the  fired  face,  but  in  a  few  the  crack  developed  near 
the  back  of  the  block  and  the  fired  face  remained  attached  to  the  web. 

The  strength  tests  of  the  fragments  of  these  blocks  are  given  in 
Table  5. 

PANEL  6  (Mortar  Building  Blocks). 

Material. — Panel  6  consisted  of  one-piece  single-air-space  blocks, 
made  in  the  same  way  and  of  the  same  proportions  and  consistencies 
as  those  previously  tested.  They  were  stored  in  a  moist  room  in  St. 
Louis  41  days  and  in  Chicago  20  days  and  were  tested  at  the  age  of 
64  days. 


26 


FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 


/OOO 
SOO 


FIGURE  5.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  5.  Tempera- 
ture: Maximum,  24°;  minimum,—!0;  mean,  12°.  Relative  humidity:  7  a.m.,  82;  7p.m. ,62.  Direction 
of  prevailing  wind,  northwest. 


U.   S.  GEOLOGICAL  SURVEY 


BULLETIN    370       PLATE   X 


A.     BACK  OF  PANEL  6,  CEMENT  MORTAR  BUILDING  BLOCKS,  AFTER 
FIRING  AND  QUENCHING. 


B.     FACE  OF  PANEL  6,   CEMENT  MORTAR    BUILDING  BLOCKS,  AFTER  FIRING 
AND  QUENCHING. 


RESULTS   OF   TESTS.  27 

Test. — Firing  started  at  12.35  p.  m.  January  29,  1907,  and  con- 
tinued for  2  hours  and  1  minute.  The  panel  was  then  quenched  with 
water  at  a  temperature  of  36°  F.  for  5  minutes.  The  fire  gave  a 
uniform  temperature  from  the  start. 

In  10  minutes  the  right-hand  and  left-hand  blocks  in  the  third 
row  spalled  off  around  the  inner  edges.  At  30  minutes  the  left-hand 
block  in  the  sixth  row  spalled  around  the  bottom  edge  to  a  depth  of 
about  1  inch;  The  spalling  extended  upward  over  the  block  to  a 
height  of  about  3  or  4  inches,  and  the  material  became  loose  and  fell 
off.  The  center  blocks  in  the  top  row  spalled  similarly,  but  less 
severely.  At  60  minutes  steam  began  to  appear  through  the  mortar 
joints. 

Curves  showing  the  variations  of  the  temperature  throughout  the 
test  are  given  in  figure  6. 

Results. — Plate  X,  B,  shows  the  face  of  the  panel  and  Plate  X,  A, 
the  back  of  the  panel  after  the  test,  and  Plate  XI,  A,  the  panel  during 
removal.  Before  quenching  the  faces  of  the  blocks  seemed  little 
affected,  but  after  the  application  of  the  water  the  surfaces  appeared 
badly  spalled  and  washed  away.  The  photograph  (PL  X,  B}  shows 
that,  as  hi  previous  tests,  the  lean  damp  blocks  were  the  most  severely 
affected,  but  the  1 : 8  wet  and  the  1 : 8  medium  suffered  little  less  than 
the  1 : 8  damp.  The  1 : 2  blocks  showed  no  signs  of  surface  cracks, 
but  were  almost  as  badly  washed  away  as  the  1 : 4  blocks.  The  1 : 2 
wet  blocks  were  affected  considerably  less  than  the  1 : 2  medium  and 
1 : 2  damp  blocks.  The  1 :  4  medium,  wet,  and  damp  blocks  seemed 
affected  about  equally.  Only  two  of  the  blocks  could  be  taken  from 
the  wall  intact.  These  were  a  1 :  4  wet  and  a  1 :  4  damp  in  the  center 
row.  All  the  others  were  cracked  across  the  end  webs,  and  in  most 
cases  the  faces  of  the  blocks  split  vertically  along  the  inner  web.  In 
a  few  cases  the  end  webs  cracked  near  the  back  face,  but  hi  all  cases 
the  center  web  remained  attached  to  the  back  face.  This  web  in 
many  cases  was  attached  to  a  small  piece  of  the  front  face,  the  front 
face  having  cracked  away  from  it  on  either  side. 

The  strength  tests  on  these  blocks  are  given  in  Table  6. 

PANEL  7  (Mortar  Building  Blocks). 

Material. — Panel  7  was  made  of  one-piece  single-air-space  blocks, 
similar  to  those  in  panel  6.  They  were  stored  in  the  moist  room  in 
St.  Louis  37  days  and  in  Chicago  23  days,  and  were  tested  at  the  age 
of  63  days.  The  panel  was  laid  up  in  freezing  weather. 

Test. — Firing  started  at  9.14  a.  m.  February  1,  1907,  and  con- 
tinued 2  hours  and  2  minutes,  after  which  the  panel  was  cooled  in 
the  air  without  quenching.  The  fire  was  apparently  uniform  over 
the  entire  panel. 


28  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


/OM 

90C 


800 
700 
600 


*       -1? 


JOO 

200 

100 

0 


FACE    OF  PANEL 


573 


FURNACE 


400 
300 


I     < 

&  /zw 


WATER   PYROMETER 


600 
SW 
<MO 

300 


BACK   OF   PANEL 


-/a 


^         ^         ^ 


§       H 


FIGURE  6.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  6.  Tempera- 
ture: Maximum,  28°;  minimum,  17°;  mean,  22°.  Relative  humidity:  1  a.  m.,  92;  7  p.  m.,  100.  Direction 
of  prevailing  wind,  southeast. 


RESULTS   OF    TESTS.  29 

There  was  no  cracking  or  spalling  up  to  70  minutes,  when  the  block 
on  the  left-hand  side  of  the  panel  in  the  eighth  row  cracked  vertically 
on  the  back  close  to  the  center  web  on  the  outer  edge.  No  crack  on 
the  fired  side  or  face  of  this  block  could  be  detected.  During  the 
remainder  of  the  test  no  other  feature  of  importance  was  observed. 

Curves  showing  the  variation  of  the  temperature  throughout  the 
test  are  given  in  figure  7. 

Results. — Plate  XI,  B,  is  reproduced  from  a  photograph  of  the  face 
of  the  panel  after  the  test;  Plate  XII,  A,  from  a  photograph  of  the 
panel  during  dismantling.  On  removing  the  door  from  the  furnace 
two  of  the  blocks  were  found  to  be  cracked.  As  the  cooling  pro- 
ceeded irregular  hair  cracks  developed  on  the  face  of  all  the  blocks, 
but  were  most  pronounced  on  the  1 : 8  damp  blocks.  In  the  1 : 2  blocks 
the  cracks  were  very  fine  and  apparently  did  not  .penetrate  to  any 
great  depth.  After  the  door  had  cooled  for  several  hours  cracks 
developed  in  each  tier,  running  vertically  through  all  the  blocks.  In 
the  left-hand  and  center  tiers  the  cracks  were  to  the  right  of  the 
center  web,  while  in  the  right-hand  tier  they  were  on  the  left  of  the 
center  web.  The  surfaces  of  the  1 :  8  blocks  were  found  to  be  so  soft 
that  they  could  be  brushed  away  with  the  finger  to  a  depth  of  about 
\  inch,  difference  in  consistency  having  had  little  effect.  The  1 : 2 
blocks  were  considerably  harder.  The  surfaces  of  the  blocks  were 
apparently  affected  by  the  heat  and  were  discolored  from  a  depth 
of  1  inch  to  H  inches  in  the  case  of  the  1 : 8,  from  f  inch  to  1}  inches 
in  the  1:4,  and  from  \  to  1  inch  in  the  1 : 2  blocks.  The  blocks  of 
wet  consistency  were  apparently  in  better  condition  than  those  of 
damp  and  medium  consistency,  but  the  difference  was  slight. 

On  dismantling  the  wall,  it  was  found  that  none  of  the  blocks  were 
intact,  all  having  cracked  across  the  webs.  In  nearly  every  case  the 
crack  across  the  web  was  near  the  face,  but  in  one  or  two  cases  it 
was  near  the  back,  the  web  remaining  attached  to  the  face. 

The  strength  tests  of  the  fragments  of  these  blocks  are  given  in 
Table  7. 

PANEL  8  (Mortar  Building  Blocks). 

Material. — Panel  8  consisted  of  one-piece  single-air-space  blocks 
made  in  the  same  manner  and  of  the  same  proportions  and  consist- 
encies as  those  previously  tested.  They  were  stored  in  a  moist 
room  in  St.  Louis  35  days  and  in  Chicago  26  days,  and  were  tested 
at  the  age  of  64  days.  The  panel  was  laid  up  in  freezing  weather. 

Test. — Firing  started  February  4,  1907,  and  continued  for  2  hours 
and  1  minute,  after  which  the  panel  was  cooled  in  air  without  the 
application  of  water.  The  fire  was  uniform  and  under  good  control. 


30 


FIEE   EESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


T/ME 


FIGURE  7.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  7.  Tem- 
perature: Maximum,  37°;  minimum,  27°;  mean,  32°.  Relative  humidity:  7  a.  m.,  91;  7  p.  m,  85.  Direc- 
tion of  prevailing  wind,  southwest. 


KESULTS   OF   TESTS.  31 

In  15  minutes  the  right-hand  block  in  the  third  row  bulged  at  the 
center,  projecting  about  j  inch,  but  no  cracks  were  visible.  At  20 
minutes,  however,  a  vertical  crack  developed  at  the  center,  and  the 
block  bulged  out  about  1  inch.  At  22  minutes  the  block  in  the  center 
of  the  third  row  spalled  on  the  lower  edge  to  a  depth  of  about  }  to  1 
inch,  and  the  spalling  extended  diagonally  toward  the  right-hand 
corner,  about  one  third  of  the  surface  becoming  loose.  The  spalling 
then  extended  toward  the  left-hand  side,  and  a  piece  about  f  inch 
in  depth  and  2  inches  wide  on  the  left  of  the  block  came  off.  At  27 
minutes  the  block  in  the  center  of  the  second  row  spalled  on  the  left 
side,  after  which  the  entire  surface  became  loose  and  fell  off.  At 
this  time  the  right-hand  block  in  the  third  row,  first  mentioned, 
bulged  about  2  niches  at  the  center,  and  the  surface  fell  off  to  a  depth 
of  about  1  inch.  The  fresh  surface  exposed  was  comparatively  smooth, 
indicating  that  a  seam  may  have  formed  in  the  manufacture  of  the 
block.  At  30  minutes  the  center  block  in  the  sixth  row  spalled,  the 
crack  starting  at  the  center  and  extending  in  both  directions  toward 
the  ends.  A  portion  about  6  inches  square  and  £  inch  deep  at  the 
center  fell  off.  At  45  minutes  the  block  in  the  center  of  the  second 
row,  above  mentioned,  bulged  out  to  about  J  inch,  and  the  remaining 
portion  of  the  face  fell  off.  At  62  minutes  the  block  in  the  second 
row  center  bulged  to  the  extent  of  about  }  inch,  and  the  remaining 
pieces  of  the  face  on  the  right-hand  side  fell  off.  The  control  of  the 
furnace  became  difficult  owing  to  the  clogging  of  the  burners  by  the 
fallen  pieces.  At  70  minutes  the  block  in  the  center  of  the  third 
row,  before  mentioned,  spalled  considerably  more,  and  a  small  piece 
to  the  left  of  the  center  at  the  bottom  fell  off.  During  the  remainder 
of  the  firing  no  further  changes  were  noted. 

The  temperature  curves  are  shown  in  figure  8. 

Results. — Plate  XII,  B,  shows  the  face  of  the  panel  after  cooling 
in  air;  a  photograph  of  the  back  showed  no  noticeable  damage. 
Plate  XIII,  B,  shows  the  condition  of  the  blocks  while  being  removed 
from  the  panel.  On  cooling,  irregular  hair  cracks  were  found  over 
the  surface  of  the  blocks,  which  were  largest  and  most  numerous  on 
the  1:8  blocks.  No  vertical  cracks  were  observed.  The  surfaces  of 
most  of  the  blocks,  as  may  be  seen  in  the  photographs,  were  found 
more  or  less  spalled,  especially  the  1:8  mixtures.  The  surfaces  could 
be  easily  broken  off  on  the  1 :  8  blocks.  The  1 : 4  blocks  were  not  so 
badly  spalled,  but  the  surfaces  could  be  crumbled  with  the  fingers. 
The  1 : 2  damp  blocks  were  slightly  spalled  on  the  edges.  The  1 : 2 
medium  and  wet  blocks  showed  no  signs  of  spalling,  but  to  a  depth 
of  |  inch  the  faces  were  soft.  The  concrete  was  discolored  by  heat 
to  a  depth  of  H  to  If  inches  in  the  1 :  8,  f  inch  to  H  inches  in  the  1 :  4, 
and  £  to  1  inch  in  the  1:2.  The  different  consistencies  of  any  one 
proportion  suffered  about  equally. 


32 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


FIGURE  8.~Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  8.  Tem- 
perature: Maximum,  17°;  minimum,  2°;  mean,  8°.  Relative  humidity:  7  a.  m.,  88;  7  p.  m.,  90-  Direc- 
tion of  prevailing  wind,  northwest. 


U.    S.    GEOLOdlCAL    SURVEY 


BULLETIN    370       PLATE   XIII 


A.     FACE  OF  PANEL  9,   CEMENT  MORTAR   BUILDING  BLOCKS,  AFTER  FIRING 
AND  QUENCHING. 


B.     PANELS,  CEMENT  MORTAR   BUILDING  BLOCKS,   DURING  DISMANTLING. 


*    *"          '  r     ' 

',       \      r     ',r,     '^     r"*frrt 


RESULTS   OF   TESTS.  33 

On  dismantling  the  panel,  it  was  found  that  every  block  had  failed 
across  the  web.  As  a  rule  the  failure  was  near  the  face,  but  one  or 
two  webs  cracked  off  at  the  back  and  remained  attached  to  the  fired 
side.  In  the  case  of  one  block  the  face  cracked  across  its  center  web, 
one  half  coming  loose  from  the  web  and  the  other  remaining  attached 
to  the  web  on  the  other  end  of  the  block.  The  small  linen  marking 
tags,  one  of  which  was  fastened  against  the  back  of  each  block  in  one 
of  the  core  holes,  were  not  damaged  at  all  by  the  test.  Three  of 
these  tags  may  be  seen  in  Plate  XIII,  B. 

The  strength  tests  on  the  fragments  of  these  blocks  are  given  in 
Table  8. 

PANEL  9  (Mortar  Building  Blocks). 

Material. — Panel  9  consisted  of  two-piece  blocks  made  in  the  same 
way  and  of  the  same  proportions  and  consistencies  as  those  pre- 
viously tested.  They  were  stored  in  the  moist  room  in  St.  Louis  32 
days  and  in  Chicago  29  days,  and  were  tested  at  the  age  of  64  days. 

The  face  of  the  panel  was  laid  up  in  three  tiers  without  breaking  the 
joints,  while  the  back  was  laid  up  with  two  tiers  of  whole  blocks  and 
two  tiers  of  half  blocks  on  each  side.  This  was  necessary  in  order  that 
the  blocks  might  be  staggered  to  bond  them.  The  views  of  the  face 
and  back  of  the  panel  (Pis.  XIII,  A,  and  XIV,  A)  show  the  arrange- 
ment of  the  blocks.  The  panel  was  laid  up  in  freezing  weather. 

Test. — The  fire  was  started  at  9.16  a.  m.,  February  7,  1907,  and 
continued  for  2  hours  and  1  ^  minutes,  after  which  water  was  applied 
for  5  minutes  at  a  temperature  of  36°  F.  A  fairly  uniform  fire  was 
obtained  from  the  start. 

For  20  minutes  there  was  considerable  snapping.  In  60  minutes 
the  right-hand  block  in  the  third  row  spalled  at  the  outer  edge.  At 
78  minutes  the  right-hand  block  in  the  sixth  row  spalled  at  the  center 
and  small  pieces  cracked  off.  No  further  change  was  observed 
during  the  remainder  of  the  test. 

The  temperature  curves  are  given  in  figure  9. 

Results.— Plate  XIII,  A,  shows  the  face  and  Plate  XIV,  A,  the 
back  of  the  panel  after  the  test,  and  Plate  XIV,  B,  the  condition  of 
the  blocks  during  removal.  On  removing  the  panel  from  the  furnace 
the  blocks  appeared  to  be  smooth  and  no  cracks  were  noticeable. 
After  the  application  of  the  water  all  the  blocks  were  cracked  through 
on  each  side  of  the  center  webs  with  the  exception  of  the  1 :  2  mixtures 
on  the  bottom  row.  The  surfaces  were  rough  and  pitted  and  washed 
away  from  J  to  J  inch  on  the  1 :2  blocks,  from  J  to  f  inch  on  the  1 :  4 
blocks,  and  from  1  inch  to  2  inches  on  the  1 : 8  blocks. 

On  dismantling  the  wall  it  was  found  that  all  the  blocks  had 
cracked  away  from  their  webs  or  the  blocks  had  cracked  on  either 
73087— Bull.  370—09 3 


34 


FIKE   RESISTANCE   OF   VAEIOUS   BUILDING   MATERIALS. 


IN  M/NUTES 

FIGURE  9. — Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  9.  Tempera- 
ture: Maximum,  24°;  minimum,  16°;  mean,  20°.  Relative  humidity:  7  a.  m.,  95;  7  p.  m.,  85.  Direction 
of  prevailing  wind,  southeast. 


lio1 

UJ  o 
5  o 


RESULTS   OF    TESTS.  35 

side  of  the  web,  leaving  a  small  piece  of  the  face  of  the  block  attached. 
The  webs  of  two  or  three  of  the  blocks  on  the  back  of  the  panel  were 
also  cracked  off.  The  1 : 8  mixtures  were  badly  crumbled  and  broken 
into  small  pieces  when  taken  from  the  wall.  This  was  true  to  a 
considerable  extent  in  the  1 : 4  blocks,  while  the  1 : 2  blocks  were  not 
broken  except  at  the  webs.  The  blocks  composing  the  back  of  the 
wall  were  apparently  undamaged  except  for  one  or  two  cracked  webs. 
The  results  of  the  strength  tests  are  given  hi  Table  9. 

PANEL  10  (Mortar  Building  Blocks). 

Material. — Panel  10  was  made  of  two-piece  blocks  exactly  like 
those  tested  in  panel  9,  but  was  not  subjected  to  the  quenching  after 
the  fire  test.  The  blocks  were  stored  in  the  moist  room  at  St.  Louis 
28  days  and  at  Chicago  32  days,  and  were  tested  at  the  age  of  63  days. 
The  panel  was  laid  up  in  freezing  weather. 

Test. — Firing  was  started  at  2.11  p.  m.,  February  11,  1907,  and 
continued  for  2  hours  and  3  minutes,  after  which  the  panel  was 
cooled  in  air,  without  the  application  of  water.  The  fire  was  fairly 
uniform,  but  not  as  hot  at  the  top  as  at  the  bottom  and  center. 

In  8  minutes  snapping  and  cracking  was  observed.  At  12  minutes 
the  second  block  in  the  second  row  spalled  at  the  center,  the  cracks 
mnning  off  at  the  edges  on  all  four  sides.  A  small  piece  about  4 
inches  long  and  ^  inch  thick  fell  out  on  the  top  edge.  The  right- 
hand  block  in  the  third  row  spalled  from  a  depth  of  about  2  inches 
along  the  edge  to  a  depth  of  about  |  inch  at  the  center.  The  left- 
hand  block  in  the  sixth  row  spalled  and -a  piece  9  inches  long,  ?  to  } 
inch  thick,  and  the  width  of  the  block,  fell  out.  At  70  minutes  steam 
l>egan  to  come  through  the  joints,  especially  at  the  top.  No  further 
change  was  observed. 

The  temperature  curves  are  shown  in  figure  10. 

Results. — Plate  XV,  A  and  B,  shows  the  face  and  back  of  the  panel 
after  the  test,  and  Plate  XVI,  A,  the  condition  of  the  blocks  during 
the  dismantling.  On  removing  the  panel  from  the  furnace  it  was 
found  that,  with  the  exception  of  the  blocks  that  had  already  spalled, 
the  surface  was  comparatively  smooth.  In  about  5  minutes  many 
hair  cracks  developed  over  the  surface  of  the  blocks.  They  were 
more  pronounced  in  the  lean  mixtures  than  in  the  rich  ones.  As 
cooling  progressed  these  cracks  became  more  pronounced  and  covered 
more  of  the  surface.  Vertical  cracks  running  along  the  webs  were  not 
present  in  this  panel.  The  surfaces  of  the  blocks  were  found  to  be 
very  soft,  especially  in  the  1 : 8  blocks,  which  could  be  easily  rubbed 
away  with  the  finger.  In  the  1 : 2  blocks  the  surface  could  be  easily 
scratched  with  a  tool  to  the  depth  of  i  inch,  in  the  1 : 4  blocks  to  a 


36 


FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 


300 


T/ME 


FIGURE  10.—  Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  10.  Tem- 
perature: Maximum,  3.3°;  minimum,  18°;  mean,  26°.  Relative  humidity:  7  a.m.,  71;  7p.m.,  64.  Direc- 
tion of  prevailing  wind,  south. 


RESULTS  OF   TESTS.  37 

depth  of  f  inch,  and  in  the  1 : 8  blocks  to  a  depth  of  1 J  inches.  The 
consistencies  apparently  had  little  io  do  with  the  behavior  of  the 
materials. 

On  dismantling  the  panel  it  was  found  that  the  blocks  had  all 
cracked  across  the  webs,  and  in  nearly  every  case  across  the  face 
near  the  webs.  The  blocks  were  not  as  a  rule  broken  in  small  pieces, 
as  was  the  case  (in  panel  9)  where  the  water  was  applied,  but  the 
surfaces  were  easily  broken  away  from  the  remainder  of  the  material. 
The  blocks  composing  the  back  of  the  panel  were  unaffected,  as  far 
as  could  be  observed,  and  only  one  or  two  of  the  webs  were  cracked  off. 

The  strength  tests  of  the  fragments  of  these  blocks  are  given  in 
Table  10. 

PANEL  H  (Brick). 

Material. — Panel  11  consisted  of  hard-burned  clay  bricks  of  good 
quality.  These  bricks  were  of  a  light  salmon  color  and  contained 
scattered  small  lime  nodules,  which  made  small  black  spots  at  the 
surface.  The  physical  properties  of  the  bricks  are  given  in  Table  11. 
In  this  table  the  transverse  strength  of  the  bricks  before  firing,  the 
compressive  strength  of  the  bricks  before  firing  and  after  firing,  the 
compressive  strength  after  being  immersed  in  water  48  hours  before 
firing,  and  the  percentage  of  moisture  absorbed  in  30  minutes,  4  hours, 
and  48  hours  are  given. 

The  panel  was  built  up  as  a  standard  12-inch  wall,  with  headers 
every  seventh  row,  cement  mortar  being  used. 

Test. — The  test  was  made  on  February  15,  1907,  and  the  firing 
continued  2  hours  and  1  minute,  after  which  the  panel  was  quenched 
in  water  for  5  minutes,  the  water  being  at  a  temperature  of  36°  F. 
The  fire  was  uniform  over  the  entire  panel. 

In  15  minutes  there  was  considerable  snapping,  which  lasted  5  min- 
utes. Xo  cracks  or  chipping  of  the  bricks  was  noticed  at  this  time. 
At  25  minutes  it  was  noticed  that  two  or  three  of  the  bricks  had  pitted 
and  that  small  pieces  of  the  surfaces  had  split  off,  showing  small  lime 
nodules,  which  had  probably  expanded  and  burst.  These  pits  were 
J  to  f  inch  deep.  At  75  minutes  part  of  the  faces  of  two  bricks 
cracked  off  and  exposed  lime  nodules  about  i  inch  in  diameter.  No 
further  changes  were  noticed. 

In  removing  the  door  a  delay  of  about  3  minutes  occurred  from 
the  time  the  fire  was  shut  off  until  the  water  was  applied,  owing  to 
the  door's  sticking.  The  12-inch  brick  panel  loaded  the  frame  some- 
what beyond  its  capacity,  so  that  the  counterweights  were  not  heavy 
enough  to  draw  the  door  out.  In  prying  the  door  from  the  furnace 
with  a  crowbar  it  was  severely  shaken,  but  apparently  none  of  the 
bricks  were  cracked  by  the  shaking.  When  the  door  was  halfway 


38 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


JOOO 
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FIGURE  11.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  11.  Tem- 
perature: Maximum,  50°;  minimum,  25°;  mean,  38°.  Relative  humidity:  7  a.  m.,  .76;  7  p.  m.,  (11. 
Direction  of  prevailing  wind,  southwest. 


KESULTS    OF    TESTS.  39 

out,  the  attempt  to  move  it  farther  was  abandoned,  and  the  water 
was  applied  to  the  half  of  the  panel  which  stuck  out  from  the  fur- 
nace. The  portion  of  the  panel  which  was  subjected  to  the  stream 
of  water  is  shown  to  the  right  of  the  vertical  line  in  Plate  XVI,  B. 

The  temperature  curves  are  given  in  figure  1 1 . 

Results. — Plate  XVI,  B,  shows  the  face  of  the  panel  after  the  test. 
About  18  or  20  per  cent  of  the  bricks  were  split  and  small  pieces  of 
the  surface  were  washed  away.  After  cooling,  60  or  70  per  cent  of 
the  bricks  were  found  to  be  cracked  and  split  sufficiently  to  permit 
picking  off  portions.  In  most  cases  this  splitting  extended  into  the 
brick  from  \  inch  to  1J  inches.  Where  water  did  not  strike  directly 
upon  the  panel,  the  bricks  wrere  not  so  badly  broken,  and  from  only 
a  small  percentage  of  them  could  portions  be  picked. 

On  dismantling  the  panel,  however,  it  was  found  that  about  60 
per  cent  of  the  bricks  not  exposed  to  the  water  were  cracked,  but 
the  depth  of  these  cracks  was  not  as  great  as  in  the  bricks  exposed 
to  the  water.  In  nearly  every  crack  a  lime  knot  was  found  at  the 
bottom.  The  bricks  on  the  back  of  the  panel  and  the  fillers  were 
apparently  unaffected,  and  the  mortar  holding  these  two  layers 
together  was  apparently  as  hard  as  before  the  test.  The  mortar  on 
the  face  was  washed  away  about  ^  inch. 

PANEL  12  (Brick). 

Material. — The  face  of  panel  12  was  composed  of  hydraulic-pressed 
bricks  of  a  dark-red  color,  uniform  in  size,  with  square  edges  and 
corners.  The  surfaces  were  fine  grained  and  free  from  knots  and 
cracks.  The  back  of  the  panel  was  composed  of  common  bricks 
taken  from  panel  11.  The  bricks  were  laid  as  an  8-inch  wall,  with 
blind  headers  every  sixth  row,  in  cement  mortar,  the  faces  being 
laid  in  lime  putty,  as  is  customary  with  this  class  of  brick.  The 
panel  was  frozen  when  the  test  began. 

The  physical  tests  of  these  bricks  are  given  in  Table  12.- 

Test. — This  panel  was  fired  February  19,  1907,  for  2  hours  and  1 
minute,  and  cooled  by  quenching  with  water  for  5  minutes,  the  water 
being  at  a  temperature  of  36°  F.  At  the  start  the  fire  was  well  dis- 
tributed and  of  a  uniform  color  throughout. 

In  15  minutes  no  snapping  had  been  noted.  During  the  entire 
test  no  cracking  or  spalling  of  the  bricks  could  be  observed.  The 
heat  was  apparently  well  distributed  except  that  there  was  a  deposit 
of  soot  on  the  lower  and  central  parts  of  the  panel. 

Curves  showing  the  variations  in  temperature  are  given  in  figure  12. 

Results. — Plate  XVII,  A,  shows  the  face  of  the  wrall  after  the  test. 
On  removal  from  the  furnace  one-third  of  the  bricks  were  badly  dis- 
colored. Only  seven  were  seen  to  be  cracked  or  pitted  before  the 
application  of  the  water,  and  these  defects  were  on  the  corners  and 


40 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


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FIGURE  12.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  12.  Tem- 
perature: Maximum,  45°;  minimum,  32°;  mean,  38°.  Relative  humidity:  7  a.  m.,  70;  7  p.  m.,  53. 
Direction  of  prevailing  wind,  west. 


KESULTS   OF   TESTS. 


41 


represented  a  very  small  area  of  the  bricks.  After  quenching  with 
water  about  18  per  cent  of  the  bricks  were  cracked  through.  None 
of  them  except  those  above  mentioned  were  found  to  be  spalled. 
After  the  test  the  wall  was  found  to  be  apparently  sound,  though 
smoke  stained.  It  could  have  been  left  standing  and  the  injured 
bricks  replaced  by  new  ones  without  impairing  its  strength. 

On  dismantling,  about  70  per  cent  of  the  bricks  were  found  to  be 
apparently  sound. 

PANEL  13  (Tile). 

Material. — Panel  13  consisted  of  semiporous  glazed  building  tile 
(figure  13),  of  a  light-brown  color,  but  of  several  shades.     The  webs 


FIGURE  13. — Sketch  of  glazed  building  tile  used  in  panel  13. 

of  the  tiles  were  more  or  less  cracked  and  checked,  especially  where 
they  joined  the  faces.  The  webs  were  very  small  and  apparently 
did  not  prevent  this  condition  of  affairs.  The  faces  were  more  or 
less  rough  and  warped. 

The  tiles  were  laid  on  an  8-inch  face,  in  cement  mortar,  with  their 
long  dimension  in  the  horizontal  plane.  The  joints  were  about  \ 
inch  and  were  broken.  This  exposed  an  8-inch  face  to  the  fire. 
The  panel  was  laid  up  in  freezing  weather. 

Tests. — The  panel  was  fired  February  26,  1907,  for  2  hours  and  1 
minute  and  quenched  with  water  for  5  minutes,  the  water  being  at  a 


42  PIKE  KESISTANCE    OF   VAKIOUS   BUILDING   MATERIALS. 

temperature  of  36°  F.  An  even  fire  was  obtained  at  the  start,  and 
the  fire  was  about  uniform  over  the  entire  panel.  No  crackling  or 
snapping  was  observed  at  any  part  of  the  test. 

In  30  minutes  a  tile  in  the  ninth  row,  third  from  the  left  side, 
split  horizontally  just  under  the  center  web.  At  50  minutes  a  tile 
in  the  center  of  the  eighth  row  spalled  on  the  surface  and  a  small 
piece  (about  2  inches)  came  off.  During  the  remainder  of;  the  test 
no  further  changes  were  observed. 

The  temperature  curves  are  given  in  figure  14. 

Results. — Plates  XVII,  B,  and  XVIII,  A,  show  the  face  and  back 
of  the  panel  after  quenching.  On  removing  the  panel  from  the  fur- 
nace none  of  the  faces  were  apparently  cracked,  but  in  the  quenching 
about  45  per  cent  of  the  faces  fell  off.  During  the  first  2  minutes  of 
the  water  treatment  the  tiles  snapped  and  crackled  appreciably,  but 
not  until  about  2  minutes  had  elapsed  did  any  of  the  faces  actually 
fall  from  the  panel. 

After  cooling,  it  was  found  that  about  80  per  cent  of  the  tiles  were 
badly  cracked;  on  gently  tapping  those  that  remained  in  place  the 
faces  came  off  many  of  them.  The  faces  that  remained  in  place 
were  found  to  be  badly  cracked,  but  firmly  attached.  The  surfaces 
of  the  tiles  had  the  same  appearance  as  before  the  fire,  except  that 
small  irregular  hair  cracks  covered  the  entire  face.  The  material 
composing  the  face  could  be  easily  broken  in  the  hand.  In  nearly 
every  case  the  webs  failed  near  the  fired  face.  In  a  few  cases  the 
failure  was  diagonally  across  the  web  where  the  web  joined  the  center 
web.  The  back  of  the  panel  was  apparently  uninjured,  and  in  but 
few  cases  were  cracks  observed  in  the  webs  lying  in  a  vertical  plane. 
The  mortar  was  washed  out  of  the  joints  from  1  inch  to  3  inches  deep, 
and  between  a  few  tiles  it  was  entirely  washed  out  so  that  the  water 
passed  through  the  joints  and  ran  down  the  back  of  the  panel. 

PANEL  14  (Mortar  Building  Blocks). 

Material. — Panel  14  consisted  of  27  "typical  Portland"  cement  and 
slag-sand  mortar  one-piece  single-air-space  blocks  made  of  a  medium 
consistency  of  1 :  1^,  1 :  2i,  and  1 : 4  mixtures.  The  specimens  were  63 
days  old  when  tested.  They  were  cured  in  a  moist  room  and  sprinkled 
twice  daily  for  14  days  and  were  then  cured  in  air,  being  protected 
from  the  sun,  for  49  days.  The  blocks  were  laid  in  fire  clay  with  the 
joints  not  broken.  This  was  done  to  avoid  cutting  the  specimens  to 
make  them  fit  the  door. 

Test. — The  panel  was  fired  on  May  23,  1907,  for  2  hours  and  2 
minutes  and  was  cooled  by  the  application  of  water  at  50°  F.  for  5 
minutes.  One  minute  elapsed  between  the  time  of  removing  the 
door  from  the  furnace  and  the  application  of  the  water.  The  tem- 
perature of  the  furnace  was  even  from  the  start.  Curves  showing 


RESULTS   OF    TESTS. 


43 


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FIGURE  14.— Diagram  showing  temperature  conditions  in  the  furnace  and  at  the  back  of  panel  13.  Tem- 
perature: Maximum,  37°;  minimum,  26°;  mean,  32°.  Relative  humidity:  7  a.  m.,  79;  7  p.  m.,  78. 
Direction  of  prevailing  wind,  southeast. 


44  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

the  various  temperatures  recorded  during  the  test  are  given  in 
figure  15. 

In  13  minutes  the  blocks  began  to  turn  dark  red.  No  snapping 
was  noted  throughout  the  test.  At  55  minutes  the  blocks  in  the 
second  row  on  the  right  end  cracked  in  lower  left  corner,  and  a  small 
piece,  about  \  inch  thick  by  2  square  inches  in  area,  fell  out.  During 
the  remainder  of  the  test  no  apparent  change  occurred. 

Results. — On  removal  of  the  panel  from  the  furnace,  before  the 
water  was  applied,  there  were  no  cracks  or  spalled  places  observed. 
The  face  of  the  panel  was  badly  smoke  stained,  especially  at  the 
bottom  and  about  halfway  up  the  panel  at  the  center.  The  effect  of 
the  water  was  to  wash  the  spalled  portion  away  to  the  depth  of  about 
i  to  f  inch  on  the  1 :  H  mixtures,  \  to  f  inch  on  the  1 :  2J  mixture, 
and  i  to  f  inch  on  the  1 : 4  mixture.  The  resulting  surfaces  were 
rough  and  pitted,  but  were  nearly  as  hard  as  the  unaffected  portions 
of  the  block.  That  the  1 :  li  proportion  had  not  been  as  well  mixed 
as  the  others  was  shown  by  small  lumps  of  cement  appearing  on  the 
surface. 

Plate  XVIII,  B,  shows  the  panel  face  after  firing,  and  Plate 
XIX,  A,  the  back  of  the  panel  after  firing.  Plate  XIX,  B,  is  repro- 
duced from  a  photograph  taken  while  dismantling  the  panel. 

Only  one  block,  a  1:4  mixture,  had  split  through  the  webs;  the 
cracks  developed  across  the  webs  close  to  the  fired  side.  The  face 
of  this  block  which  had  been  exposed  to  the  fire  was  apparently  un- 
cracked  and  was  lifted  from  the  wall  intact.  The  remainder  of  the 
blocks  were  strong  enough  to  be  handled  and  were  later  tested  for 
transverse  and  compressive  strength. 

PANEL  15  (Mortar  Building  Blocks). 

Material. — Panel  15  consisted  oi  27  mortar  blocks  made  on  a 
single-air-space  block  machine.  A  medium  consistency  was  used  for 
the  three  mixtures,  1:2,  1:4,  1:8,  "typical  Portland"  cement  and 
Meramec  River  sand  being  the  ingredients.  The  specimens  were 
cured  in  a  moist  room  for  10  days  and  in  air  protected  from  the  sun's 
rays  for  53  days,  making  them  63  days  old  when  tested. 

Test— The  panel  was  fired  at  9.12  a.  m.  May  27,  1907,  for  2  hours 
and  1  minute,  at  the  end  of  which  time  a  stream  of  water  at  51°  F. 
was  played  on  the  hot  wall  for  5  minutes.  One  minute  elapsed 
between  the  time  the  furnace  was  shut  down  and  the  application  of 
the  water. 

The  blocks  were  laid  in  fire  clay  without  breaking  the  joints.  The 
temperature  of  the  whole  panel  was  quite  uniform  from  the  start. 
No  snapping  was  observed  during  the  test  and  no  spalling  or  cracking 
was  observed  up  to  the  time  of  the  application  of  water. 


O- 


KESULTS   OF    TESTS. 


45 


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FIGURE  15. — Diagram  showing  temperature  conditions  in  the  furnace  and  at  the  back  of  panel  14.  Tern 
perature:  Maximum,  51°;  minimum,  46°;  mean,  48°.  Relative  humidity:  7a.  m.,  97;  7  p.m.,  94.  Direc 
tion  of  prevailing  wind,  northeast. 


46  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

Curves  showing  the  variations  of  temperature  observed  during  the 
test  are  given  in  figure  16. 

Results. — In  removing  the  panel  from  the  furnace  it  failed  to  slide 
clear,  and  consequently  a  strip  about  10  inches  wide  on  the  left  side 
was  not  exposed  to  the  direct  stream  of  water.  The  1 : 2  mixture 
spalled  to  a  depth  of  about  J  to  J  inch,  the  1 : 4  to  about  f  inch  to  2 
inches,  and  the  1 :8  about  the  same  as  the  1 :4.  On  all  the  1  ^speci- 
mens portions  of  the  surface  remained  intact,  but  were  covered  with 
small  hair  cracks  and  could  be  easily  crumbled  with  the  fingers. 
The  remainder  of  the  blocks  were  hard,  but  in  every  case  they  were 
badly  cracked  and  pitted.  This  was  particularly  true  of  the  1:8 
mixtures.  One  block  of  a  1 :8  mixture,  in  the  seventh  row,  right-hand 
side,  was  cracked  on  the  back  side.  This  was  the  only  specimen 
which  cracked  in  this  manner  in  any  of  the  tests  on  mortar  blocks. 

Plate  XX,  A,  shows  the  face  of  the  wall  after  firing,  and  Plate 
XX,  B,  shows  the  condition  of  the  wall  while  being  dismantled.  On 
taking  down  the  panel  it  was  found  that  all  the  blocks  except  one  1 : 8 
block  had  cracked  across  the  web  at  the  fired  side.  One  web  of  this 
block  was  cracked  on  the  fired  side,  while  the  other  cracked  across  to 
the  back  side  of  the  block.  The  faces  of  all  the  1 : 8  blocks  crumbled 
and  fell  to  pieces  when  removed  from  the  panel,  and  a  few  of  the  1 : 4 
blocks  were  found  to  be  cracked  through  the  fired  side.  This  was 
also  found  to  be  the  case  with  one  of  the  1:2  blocks.  The  portions 
of  the  blocks  on  the  fired  side  were  seemingly  intact  and  hard,  but  on 
gentle  tapping  could  be  broken  into  very  small  pieces.  The  back 
surfaces  and  the  attached  webs  were  as  hard  as  before  the  fire  treat- 
ment, and  there  was  apparently  no  change  in  their  condition. 

PANEL  16  (Mortar  Building  Blocks). 

Material. — Panel  16  was  composed  of  27  one-piece  single-air-space 
building  blocks,  9  each  of  1:2,  1:4,  and  1:8  "typical  Portland" 
cement  and  Meramec  River  sand.  These  blocks  were  tested  when  63 
days  old,  having  been  cured  in  a  moist  room  for  3  days,  being  sprinkled 
twice  daily,  in  air  under  cover  for  7  days  and  exposed  to  the  weather, 
but  protected  from  the  direct  rays  of  the  sun  for  53  days. 

Test.— The  fire  was  started  at  1.19  p.  m.  May  28,  1907,  and  con- 
tinued for  2  hours  and  1  minute.  Immediately  on  removing  the 
panel  from  the  furnace  it  was  quenched  by  a  stream  of  water  at  51° 
F.  for  5  minutes.  No  snapping  was  observed  during  the  test. 

In  40  to  45  minutes  a  black  spot  was  observed  on  the  right  side 
and  about  the  middle  of  the  panel,  indicating  a  drop  in  temperature 
at  this  point.  At  60  minutes  the  burner  on  the  right  side  of  the  fur- 
nace became  clogged  and  caused  the  temperature  on  that  side  of  the 
panel  to  drop  a  little.  The  black  spot  above  mentioned  had  disap- 
peared in  the  interval.  At  70  minutes  the  furnace  was  readjusted 


RESULTS   OF   TESTS. 


FIGURE  16.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  15.  Tem- 
perature: Maximum,  o2°;  minimum,  38°;  mean,  45°.  Relative  humidity:  7  a.  m.,  83;  7  p.  m.,  64.  Direc- 
tion of  prevailing  wind,  northwest. 


48  FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 

and  the  right-hand  side  of  the  panel  was  brought  up  to  the  normal 
temperature.  No  signs  of  spalling  were  noticed  up  to  the  time  the 
panel  was  removed  from  the  furnace. 

Curves  showing  the  variations  of  temperature  observed  during  the 
test  are  given  in  figure  17. 

Results. — On  taking  the  panel  down  it  was  found  that  all  the  blocks 
had  cracked  across  the  webs  and  that  the  faces  of  all  the  1 : 8  mix- 
tures were  so  badly  cracked  that  these  blocks  could  not  be  removed 
intact.  On  gently  tapping  the  material  it  fell  to  pieces  and  crumbled 
very  badly.  Two  or  three  of  the  1 : 4  blocks  behaved  in  a  similar 
manner,  but  each  half  of  the  1:2  specimens  was  removed  intact. 
The  back  half  of  all  the  blocks  was  apparently  unaffected  and  free 
from  cracks. 

Plate  XXI,  A,  shows  the  face  of  the  panel  after  the  test.  Plate 
XXI,  B,  shows  the  panel  being  removed  from  the  door.  On  the 
application  of  water  the  face  of  the  1 : 4  and  1 : 8  blocks  spalled  to  the 
depths  of  |  to  1  inch  and  1  inch  to  2  inches,  respectively.  On  two  of 
the  1 : 2  mixtures  part  of  the  face  was  left  apparently  intact,  but  on 
examination  it  was  found  that  this  part  crumbled  easily  in  the  hand. 
With  the  exception  of  the  surface  the  remaining  concrete  was  found 
to  be  quite  hard.  There  were  apparently  no  vertical  cracks  running 
through  any  of  the  blocks. 

PANEL  17  (Concrete). 

Materials. — Panel  17  consisted  of  four  kinds  of  concrete,  as  follows: 
A  1:2:4  medium  consistency  (10  per  cent  water)  limestone  crushed  to 
pass  a  f -inch  screen  and  be  retained  on  a  J-inch  screen ;  a  1 : 2 : 4  medium 
consistency  (21  per  cent  water)  cinder  containing  24.5  per  cent  of 
combustible  material.  These  cinders  were  screened  to  pass  a  1^-inch 
screen;  a  1:2:4  medium  consistency  (9  per  cent  water)  granite 
crushed  to  pass  a  }-inch  screen  and  remain  on  a  J-inch  screen;  a 
1:2:4  medium  consistency  (9  per  cent  water)  gravel  screened  to  pass 
a  f-inch  screen  and  remain  on  a  J-inch  screen. 

The  sand  and  cement  mixed  with  the  above  coarse  aggregates  were 
Meramec  River  sand  and  "typical  Portland"  cement.  The  specimens 
fired  were  sections  of  plain  beams  previously  tested  in  the  Govern- 
ment's structural-materials  testing  laboratories  at  St.  Louis.  They 
measured  8  by  11  inches  in  cross  section  and  varied  in  length  from 
18  to  36  inches.  The  test  pieces  were  laid  in  fire  clay  on  their  8-inch 
side,  thus  exposing  the  11-inch  face  to  the  fire.  This  arrangement 
permitted  a  section  22  inches  high  by  6  feet  long  of  each  material, 
except  the  limestone  concrete,  to  be  exposed  to  the  fire  in  the  same 
panel.  Only  one  piece  of  the  limestone  concrete,  about  20  inches 
long,  was  tested,  as  that  was  all  of  this  character  of  concrete  which 
could  be  obtained  at  the  time  the  shipment  was  made  from  St.  Louis. 


BULLETIN    370       PLATE    XXI 


A.     FACE  OF  PANEL  16,  CEMENT  MORTAR  BUILDING  BLOCKS,  AFTER  FIRING  AND 

QUENCHING. 


B.     PANEL  16,  CEMENT  MORTAR  BUILDING  BLOCKS,   DURING    DISMANTLING. 


RESULTS   OF   TESTS. 


FACE   OF  PANEL 


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WATER   PYROMETER 


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FIGUBE  17.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  16.  Tem- 
perature: Maximum,  65°;  minimum,  45°;  mean,  55°.  Relative  humidity:  7  a.  m.,  66;  7  p.  m.,  51.  Direc- 
tion of  prevailing  wind,  southwest. 

73087— Bull.  370—09 4 


50  FIRE   RESISTANCE 'OF   VARIOUS   BUILDING   MATERIALS. 

Test. — The  firing  was  started  at  10.52  a.  m.  June  1,  1907,  and 
continued  for  2  hours  and  3  minutes,  after  which  the  panel  was 
quenched  with  water  for  5  minutes.  The  temperature  of  the  water 
was  52°  F. 

At  the  start  of  the  test  the  back  of  the  panel  was  wet,  owing  to  rain 
the  night  previous.  The  burners  started  with  a  fairly  uniform 
temperature  and  under  good  control ;  the  top  was  not  as  hot,  however, 
as  the  lower  part  of  the  panel.  In  25  minutes  a  slight  pitting  was 
noticed  on  all  four  kinds  of  concrete  and  small  pieces,  about  |  inch 
deep  and  1  inch  in  area,  fell  out  from  the  faces.  The  cinder  concrete 
developed  bright  red  spots,  from  which  small  flames  issued.  These 
spots  covered  the  greater  part  of  the  surface  of  the  cinder  concrete  and 
were  about  8  or  10  inches  apart.  At  45  minutes  steam  was  noticed 
passing  through  the  joints  on  the  back  of  the  wall.  At  65  minutes  the 
cinder  concrete  was  quite  badly  pitted,  though  of  a  uniform  color,  the 
entire  surface  having  attained  the  same  color  as  the  bright  red  spots 
before  mentioned.  A  number  of  small  bulges  projected  out  from  the 
wall  about  J-  to  J  inch.  Pits  developed  as  these  bulging  portions  fell 
away.  The  limestone  and  gravel  concrete  were  pitted  all  over  to  a 
depth  of  \  to  J  inch. 

Curves  showing  the  variations  of  temperature  observed  during  the 
test  are  given  in  figure  18. 

Results. — On  the  application  of  water  portions  of  the  surface  of  all 
four  varieties  of  concrete  washed  away.  The  limestone  washed  away 
from  J  to  J  inch,  but  the  remaining  surface  was  very  smooth  and  the 
exposed  stones  showed  the  effect  of  calcination.  The  surrounding 
concrete,  however,  was  apparently  hard,  free  from  cracks,  and 
showed  no  signs  of  discoloration  or  calcination.  The  surface  had  very 
much  the  appearance  of  concrete  which  has  been  vigorously  brushed 
while  green. 

The  stone  was  discolored  to  a  depth  of  about  1  inch.  Back  of  this 
the  stone  did  not  show  any  signs  of  heat  treatment.  The  material  on 
the  surface  had  a  very  dead  sound  when  tapped  gently  with  the 
hammer,  but  on  the  back  side  it  had  the  usual  metallic  ring. 

In  the  case  of  the  gravel,  where  the  mortar  portion  of  the  concrete 
was  rather  deep,  the  surface  was  still  intact,  but  the  greater  portion  of 
the  surface  was  pitted  and  washed  away  to  an  average  depth  of 
J  inch.  The  surface  was  very  rough  and  the  exposed  pieces  of  gravel 
were  dark  brown  and  very  easily  broken  under  a  hammer.  In 
several  cases  tfyey  were  split  and  parts  of  the  stone  could  be  pulled  out 
with  the  fingers.  The  particles  of  gravel  in  the  concrete  were  dis- 
colored to  a  depth  of  about  4  inches.  The  mortar  in  this  layer  was 
apparently  normal,  and  appeared  as  hard  as  that  of  the  unaffected 
product.  It  was  but  slightly  cracked  on  the  surface  only.  Through- 
out all  the  pieces  vertical  cracks  running  back  from  the  fired  side 


RESULTS    OF   TESTS. 


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FIGURE  18.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  17.  Tem- 
perature: Maximum,  56°;  minimum,  50°;  mean,  53°.  Relative  humidity:  7  a.  m.,  94;  7  p.  m.,  100. 
Direction  of  prevailing  wind,  northeast. 


52  FIRE  RESISTANCE   OF  VARIOUS  BUILDING  MATERIALS. 

were  observed;  they  were  about  4  to  10  inches  apart  and  extended 
back  from  the  face  about  2  to  4  inches.  They  were  nearly  straight 
in  direction  and  could  be  found  on  both  the  bottom  and  top  of  each 
beam.  The  face  of  the  portion  in  which  the  gravel  was  discolored 
had  a  very  dead  sound  when  tapped  with  a  hammer,  while  the  back 
had  a  good  metallic  ring. 

In  the  case  of  the  granite  there  was  a  considerable  portion  from 
which  the  mortar  surface  had  not  been  washed  away.  The  remain- 
ing surfaces  were  washed  away  about  J  to  f  inch.  The  exposed  pieces 
of  stone  were  slightly  discolored,  being  lighter  than  the  unaffected 
material,  but  in  most  cases  were  hard  and  broke  but  little  more 
easily  than  the  unheated  ones.  The  mortar  was  soft  and  crumbled 
about  1J  inch.  For  about  3  inches  in  from  the  face  the  mortar  had 
turned  a  light  straw  color,  but  was  quite  hard.  For  about  6  inches 
from  the  face  the  concrete  had  a  whitish  tinge,  which  indicated  that 
the  free  moisture  had  been  driven  entirely  out.  This  whitish  layer 
was  apparently  as  hard  as  the  layer  on  the  back.  To  a  depth  of 
about  2  inches  the  pieces  of  stone  had  a  rather  cloudy  look. 

Vertical  cracks  ran  directly  back  from  the  face  on  both  the  top  and 
bottom  of  the  beam ;  they  were  from  2  to  6  inches  apart  and  extended 
back  from  the  face  4  inches.  By  tapping,  the  beams  could  be  broken 
across  these  cracks.  The  face  had  a  very  dead  sound  when  tapped 
with  the  hammer;  the  back  had  the  usual  metallic  ring. 

In  the  case  of  the  cinder  a  part  of  the  face  was  still  intact  after  the 
application  of  water.  However,  it  is  very  likely  that  the  upper  left- 
hand  corner  was  more  or  less  protected  from  the  intense  heat  to  which 
the  remainder  of  the  panel  was  subjected.  On  the  other  parts  of  the 
cinder  concrete  the  spalling  from  the  fire  and  water  was  from  J  to  1J 
inches  deep.  The  surface  was  rough  and  very  badly  pitted,  although  no 
cracks  could  be  observed.  For  about  an  inch  the  concrete  was  black 
and  looked  very  spongy,  because  the  particles  of  combustible  material 
had  been  entirely  burned  out.  In  a  layer  about  J  to  f  inch  in  depth, 
directly  behind  this  spongy  layer,  the  concrete  was  black  and  looked  as 
if  it  had  been  badly  smoked.  The  combustible  material  in  the  center  of 
this  layer  was  caked.  Back  of  this  layer  was  a  strip  3  to  3J  inches  wide 
showing  no  discoloration,  but  the  mortar,  whiter  than  the  normal 
concrete,  indicated  that  the  uncombined  water  had  been  driven  away. 
The  remainder  of  the  beam  was  apparently  normal. 

Vertical  cracks  running  back  from  the  fired  face  were  found  in  only 
two  or  three  cases,  and  extended  back  only  from  2  to  4  inches.  The 
surface  had  a  very  dead  sound  and  could  be  easily  crumbled,  while  the 
back  of  the  beam  was  unaffected  and  had  the  usual  metallic  sound. 

Plate  XXII  shows  the  face  and  the  back  after  quenching. 


U.    S.    GEOLOGICAL   SURVE 


BULLETIN    370       PLATE   XXII 


A.     BACK  OF  PANEL  17,   CONCRETE  WITH   DIFFERENT  AGGREGATES,  AFTER 
FIRING  AND  QUENCHING. 


B.     FACE  OF  PANEL  17,  CONCRETE  WITH    DIFFERENT  AGGREGATES,  AFTER 
FIRING  AND  QUENCHING. 


RESULTS   OF  TESTS.  53 

PANEL  18  (Concrete). 

Material. — Panel  18  was  made  up  of  short  lengths  of  plain  granite 
concrete  beams  8  by  1 1  inches  in  cross  section  and  in  lengths  varying 
from  18  inches  to  2|  feet.  The  concrete  was  a  1:2:4  mixture  of 
" typical  Portland"  cement,  Meramec  River  sand,  and  Missouri 
red  granite,  mixed  to  a  medium  consistency  (about  9  per  cent  water) . 
The  stone  was  screened  to  pass  a  f-inch  screen  and  be  retained  on  a 
J-inch  screen.  The  panel  was  laid  up  in  fire  clay  with  broken  joints. 
The  specimens  were  laid  on  their  8-inch  side,  thus  exposing  the 
11-inch  face  to  the  fire. 

Test. — The  test  occurred  on  June  10,  1907,  and  firing  continued  for 
2  hours  and  \  minute.  After  firing  the  face  of  the  panel  was 
quenched  with  water  at  51°  F.  for  5  minutes. 

In  15  minutes  snapping  was  noted,  which  continued  for  about  5 
minutes.  At  25  minutes  hot  water  was  forced  back  through  the 
joints  and  washed  off  the  fire  clay,  which  held  the  back-wall  ther- 
mometers in  place.  This  water  was  considerably  warmer  than  the 
back-wall  surface,  consequently  the  thermometers  there  attached 
showed  unduly  high  temperatures.  At  40  minutes  the  top  of  the 
panel  began  to  dry  out,  the  bottom  portion  still  remaining  wet  with 
the  water  which  leaked  through  the  joints.  At  63  minutes  a  slight 
spalling  was  observed  in  several  places,  principally  at  the  top  of  the 
wall.  At  75  minutes  the  back-wall  face  of  the  panel  had  entirely 
dried  out,  but  steam  came  through  the  joints  on  the  top  of  the 
panel.  During  the  remainder  of  the  time  no  further  change  was 
noted. 

Curves  showing  the  variations  in  temperature  observed  during 
the  test  are  given  in  figure  19. 

Results. — After  quenching  with  water  it  was  found  that  some  por- 
tions of  the  surface  of  the  concrete  had  spalled  and  had  been  washed 
away,  while  in  other  places  the  surface  was  nearly  all  intact  and  the 
mortar  still  adhered ;  but  it  was  cracked,  and  crumbled  easily  in  the 
fingers.  The  exposed  particles  of  stone  were  found  to  be  of  a  cloudy 
whitish  color  and  quite  hard,  although  more  easily  broken  than  the 
unchanged  stone.  The  stone  had  whitened  to  a  depth  of  about  1  inch 
and  the  mortar  to  about  3  J  inches. 

Vertical  cracks  running  back  from  the  fired  face  occurred  about 
4  to  6  niches  apart,  and  extended  back  from  the  face  about  4  inches. 
By  tapping  with  a  hammer  the  beam  could  be  broken  where  these 
cracks  occurred.  The  surface  had  a  very  dead- sound  when  tapped 
with  the  hammer,  but  the  back  was  apparently  normal. 

Plate  XXIII,  A  and  B,  shows  the  face  and  back  of  the  panel  after 
firing. 


54 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


300 


T/M£/M  M/NVTES 

FIGURE  19. — Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  18.  Tem- 
perature: Maximum,  79°;  minimum,  58°;  mean,  08°.  Relative  humidity:  7  a.  m.,  78;  7  p.  in.,  79.  Direc- 
tion of  prevailing  wind,  southeast. 


RESULTS   OF   TESTS.  55 

PANEL  19  (Concrete). 

Material. — Panel  19  was  composed  of  similar-sized  sections  of 
gravel  concrete  beams,  laid  as  described  for  panel  18.  The  mixture 
and  consistency  were  the  same  as  in  panel  18,  being  1:2:4  medium 
consistency.  The  gravel  passed  a  f-inch  screen  and  was  retained 
on  a  |-inch  screen,  and  was  of  the  Meramec  flint  variety. 

Test. — The  test  took  place  on  June  11,  1907,  at  2.25  p.  m.,  and 
continued  for  2  hours  3  minutes,  followed  by  quenching  with  water 
at  53°  F.  for  5  minutes.  At  the  outset  the  temperature  at  the  top  of 
the  panel  seemed  higher  than  that  at  the  bottom. 

In  16  minutes  water  came  through  the  joints  on  the  back  of  the 
wall  and  ran  down,  washing  away  the  fire  clay  holding  the  thermome- 
ter in  place.  Up  to  25  minutes  no  snapping  had  occurred.  At  45 
minutes  the  greater  part  of  the  surface  of  the  concrete  had  spalled 
and  pitted  in  small  spots.  These  small  pits  exposed  stones  which  had 
probably  cracked  and  expanded  sufficiently  to  force  the  mortar  away 
from  the  face.  At  80  minutes  the  pitting  and  cracking  away  of 
small  portions  of  the  surface  was  very  general  over  the  lower  and 
left-hand  side  of  the  panel.  No  further  change  was  noted  and  the 
surface  of  the  panel  seemed  to  resist  any  further  pitting. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  20. 

Results. — Plate  XXIV,  A  and  B,  shows  the  face  and  back  of  the 
panel  after  the  test.  On  the  application  of  water  the  surface  washed 
away  on  the  lower  and  left  side  of  the  panel,  while  on  the  upper  and 
right  side  the  surface  was  less  severely  affected.  Particles-  of  gravel 
were  discolored  to  a  depth  of  2^  to  3  inches,  turning  a  dark  reddish- 
brown,  while  the  mortar  surrounding  them  remained  about  normal. 
Many  gravel  stones  on  the  surface  had  split,  but  were  apparently  as 
hard  as  the  sound  ones.  Vertical  cracks  from  2  to  4  inches  apart 
ran  back  from  the  face  to  a  distance  of  about  3  inches.  These  cracks 
could  be  opened  up  by  tapping,  and  the  layer  containing  the  discolored 
gravel  could  be  cracked  off  from  the  surface  of  the  beam  with  a 
hammer.  The  back  portions  of  the  beams  were  not  affected  and  had 
a  good  solid  metallic  ring,  while  the  fired  side  sounded  dead  when 
struck  with  a  hammer.  Where  the  mortar  had  not  been  washed 
away  the  surface  was  covered  with  fine  hair  cracks  and  the  material 
could  be  crumbled  in  the  ringers.  The  gravel  under  this  coating 
of  mortar  was  not  cracked,  but  was  somewhat  discolored. 

PANEL  20  (Concrete). 

Material. — Panel  20  wa~s  made  up  of  IJ-inch  to  2^-foot  lengths  of 
cinder  concrete  beams,  8  by  11  inches  in  section,  laid  on  the  8-inch 
face.  The  concrete  was  of  "typical  Portland"  cement,  Meramec 


56 


FIRE   RESISTANCE   OF    VARIOUS   BUILDING   MATERIALS. 


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FIGURE  20.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  19.  Tem- 
perature: Maximum,  78°;  minimum,  59°;  mean,  68°.  Relative  humidity:  7  a.  in.,  75;  7  p.m.,  90.  Direc- 
tion of  prevailing  wind,  west. 


RESULTS   OF   TESTS.  57 

River  sand,  and  soft  coal  cinders,  containing  24.5  per  cent  of  com- 
bustible material.  The  proportions  were  1:2:4  by  volume.  The 
cinders  were  screened  to  pass  a  l£-inch  screen  and  be  retained  on  a 
£-inch  screen.  The  top  row  in  the  panel  was  composed  of  granite, 
gravel,  and  terra-cotta  tile  and  was  put  in  merely  to  fill  up  the  space 
due  to  a  shortage  of  the  cinder  specimens. 

Test. — The  panel  was  fired  at  11.54  a.  m.  June  17,  1907,  for  2  hours 
2f  minutes,  and  was  cooled  by  quenching  with  water  at  57°  F.  for 
5  minutes. 

In  7  minutes  the  concrete  snapped  quite  badly  and  one  or  two 
small  explosions  forced  off  small  portions  of  the  surface  of  the  beams. 
No.  7  couple  was  more  exposed  than  usual  on  account  of  the  fire-clay 
mounting  being  cracked  off  by  a  piece  of  the  surface  of  the  cinder 
concrete  which  blew  across  the  furnace.  At  18  minutes  all  the  cinder- 
concrete  surface  had  begun  to  pit  and  pieces  about  1  inch  in  area 
and  |  to  |  inch  in  depth  fell  out.  A  piece  on  the  second  row  from 
the  bottom,  about  6  niches  square  and  J  inch  in  depth,  was  forced 
off  with  considerable  violence,  exposing  several  pieces  of  unburned 
coal.  This  was  followed  by  several  small  explosions,  and  a  piece  of 
the  surface  about  8  inches  square  and  £  inch  thick,  just  adjoining 
the  above-mentioned  piece,  came  off.  Small  bright-red  spots  from 
which  flames  issued  were  distributed  over  the  surface.  At  30  min- 
utes the  burners  became  more  or  less  clogged  from  the  small  pieces  of 
concrete  which  had  fallen  into  them.  This  somewhat  impaired  the 
control  of  the  furnace.  At  40  minutes  the  spalling  became  general 
over  the  surface  and  many  small  pieces  of  concrete  continued  to  fall 
from  the  panel.  The  color  became  bright  red  and  the  small  spots 
were  no  longer  visible. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  21. 

Results. — On  removal  of  the  door  it  was  found  that  the  greater 
part  of  the  surface  of  the  cinder  concrete  had  cracked  off;  during  the 
application  of  water  a  considerable  portion  of  the  surface  was  washed 
away,  apparently  to  about  the  same  depth  (J  inch).  A  very  small 
portion  of  the  face  of  each  beam  was  still  intact,  but  this  portion  was 
porous  and  crumbled  easily  in  the  hand.  The  surface  was  rough  and 
the  concrete  was  spongy  and  black  to  a  depth  of  about  1  inch.  The 
mortar  in  this  layer  was  easily  crumbled  in  the  fingers.  A  layer  3  to* 
4  inches  thick  back  of  this  was  discolored,  being  turned  almost  black, 
and  the  particles  of  combustible  material  were  practically  turned  to 
coke.  The  mortar  in  this  layer  was  apparently  hard.  The  remain- 
der of  the  beam  was  about  normal. 

Plate  XXV,  A  and  B,  shows  the  face  and  back  of  the  panel  after 
testing.  A  few  vertical  cracks  running  back  from  the  face  of  the 
beams  were  not  very  regular  and  did  not  open  up  readily  when 


58 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


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T/ME  /N  M/Nl/r£S 

FIGURE  21.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  20.  Tem- 
perature: Maximum,  91°;  minimum,  70°;  mean,  80°.  Relative  humidity:  7  a.  in.,  58;  7  p.  m.,  41.  Direction 
of  prevailing  wind,  southwest. 


RESULTS   OF   TESTS.  50 

tapped  rather  hard  with  a  hammer.  The  face  of  the  concrete  crum- 
bled when  tapped,  while  the  back  gave  a  good  sound  metallic  ring. 
The  affected  portion — that  isr  a  layer  about  2^  Laches  thick — could 
be  separated  from  the  unaltered  portion  by  tapping  on  the  edges  of 
the  piece. 

PANEL  21  (Sandstone). 

Material. — Panel  21  consisted  of  pieces  of  cut  sandstone,  7}  by  4 
by  24  inches,  laid  on  the  natural  bed  in  cement  mortar,  with  the 
7 f -inch  face  to  the  fire.  The  joints  were  broken. 

Test. — The  panel  was  fired  at  3.03  p.  m.  June  21,  1907.  for  23 
minutes. 

In  10  minutes  the  wall  bulged  in  toward  the  fire  at  the  center  of 
the  panel  about  2  inches  and  at  the  edges  about  1^  inches.  No 
snapping  was  noted  up  to  this  time.  At  19  minutes  a  vertical  crack 
in  the  fifth  row  in  the  center  gradually  developed  through  the  mortar 
joints  and  extended  into  the  pieces  in  the  third  and  seventh  rows. 
At  21  minutes  vertical  cracks  developed  in  the  seventh  row  on  the 
left  side,  about  8  inches  from  the  edge  of  the  panel,  and  rapidly 
extended  the  entire  length  of  the  panel.  A  crack  simultaneously 
developed  on  the  other  side  of  the  wall  about  the  same  distance  from 
the  edge,  running  vertically  from  top  to  bottom.  At  23  minutes  the 
panel  unexpectedly  collapsed,  falling  into  the  fire  chamber.  The 
failure  occurred  by  reason  of  the  joint  in  the  fifth  row  opening  and 
allowing  the  bottom  portion  of  the  panel  to  fall  forward  into  the 
chamber;  then  the  top  portion  fell  directly  down.  Although  the 
panel  appeared  very  weak,  there  was  no  snapping  or  crackling  up  to 
the  time  of  the  failure,  and  consequently  the  thermometers  attached 
to  the  back  side  of  the  wall  and  thermal  couples  inserted  through  it 
were  not  removed.  The  failure  carried  these  down  and  broke  all 
the  thermometers  and  cold  junction  bottles.  The  thermal  couples, 
fortunately,  were  uninjured. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  22. 

Results. — After  the  collapse  it  was  found  that  in  all  the  test  pieces 
cracks  had  developed  across  the  face  vertically  and  extended  back 
within  about  1  inch  of  the  back  side.  Horizontal  cracks  along  the 
bedding  of  the  stone  also  developed,  and  by  falling  the  layers  were 
broken  into  small  but  rather  regular  pieces.  The  test  pieces  that  did 
not  break  in  two  were  found  to  be  warped  from  -fa  to  J  inch  at  the 
center,  the  bulging"  being  toward  the  fired  side. 

The  material  was  turned  a  light  reddish  brown  to  a  depth  of  about 
f  to  1  inch  on  the  fired  side.  The  surface  was  apparently  as  hard  as 
before  being  subjected  to  the  fire,  and  there  was  no  evidence  of 
spalling  or  pitting.  The  surface  was,  however,  very  badly  cracked 


60  FIRE  RESISTANCE   OF  VARIOUS  BUILDING  MATERIALS. 


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FIGURE  22.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  21.  Tem- 
perature: Maximum,  88°;  minimum,  67°;  mean,  78°.  Relative  humidity:  7  a.  m.,  73;  7  p.  iu.,  53. 
Direction  of  prevailing  wind,  southwest. 


BESULTS   OF   TESTS.  61 

along  the  bedding  of  the  stone,  and  also  in  lines  vertical  to  this 
direction.  No  irregular  hair  cracks  were  observed.  Plate  XXVI,  A, 
shows  the  face  before  testing.  Plate  XXVI,  B,  shows  the  wall  after 
its  collapse. 

PANEL  22  (Brick). 

Material. — Panel  22  consisted  of  common  St.  Louis  brick  from  the 
foundation  of  the  briquetting  machine  at  the  Government's  fuel- 
testing  plant  at  St.  Louis,  where  they  had  been  placed  about  three 
years  before  they  were  tested  for  their  fire-resisting  properties. 
Physical  tests  of  the  bricks  are  given  in  Table  13.  The  bricks  were 
laid  in  cement  mortar  with  J-inch  joints  in  a  standard  8-inch  wall, 
and  bonded  every  sixth  row.  It  was  decided  that  a  12-inch  wall 
was  too  heavy  for  the  apparatus. 

Test. — The  panel  was  fired  June  24,  1907.  The  duration  of  fire 
was  2  hours  and  1  minute;  then  the  panel  was  cooled  by  quenching 
with  water  for  5  minutes.  The  temperature  of  the  water  was  59°  F. 
The  test  was  started  at  2.20  p.  m.  A  good  uniform  fire  was  obtained 
at  the  start. 

In  20  minutes  a  slight  snapping  was  observed.  At  30  minutes 
steam  appeared  through  cracks  on  the  back  of  the  wall.  At  50 
minutes  the  end  of  one  of  the  header  bricks  cracked  and  fell  off.  The 
piece  was  about  1  inch  in  depth.  No  further  changes  were  observed 
up  to  the  time  of  removing  the  panel. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  23. 

Results. — About  15  per  cent  of  the  faces  of  the  brick  cracked  and 
washed  off  during  the  application  of  the  water.  After  cooling,  it  was 
found  that  about  50  per  cent  of  the  faces  were  cracked  and  were 
easily  pulled  off  with  the  fingers,  or  by  prying  gently  with  a  screw- 
driver. The  headers  which  seemed  most  damaged  were  split  back 
about  1  inch.  Some  were  cracked  to  a  depth  of  2  J  inches.  The  faces  of 
all  the  bricks  were  checked  and  cracked,  and  wherever  a  piece  fell  out 
it  was  usually  about  1  inch  in  thickness.  The  entire  wall  was  dis- 
colored to  a  depth  of  about  1  inch,  the  faces  of  the  bricks  turning 
almost  black.  The  bricks  on  the  back  of  the  wall  were  apparently 
uninjured,  no  cracks  being  observed  in  any  of  them. 

Plate  XXVII,  A,  shows  the  face  of  the  panel  before  firing  and 
Plate  XXVII,  B,  shows  the  face  after  quenching. 

PANEL  23  (Granite  Building  Stone). 

Material. — Panel  23  was  composed  of  blocks  of  building  granite 
laid  in  cement  mortar  with  broken  joints. 

Test.— The  test  took  place  on  June  26,  1907.  The  duration  of  the 
fire  was  2  hours  and  4-  minute,  after  which  the  panel  was  quenched 
for  5  minutes  with  water  at  57°  F. 


62 


FIRE   RESISTANCE    OF    VARIOUS   BUILDING   MATERIALS. 


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FIGURE  23.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of 
perature:  Maximum,  80°;  minimum,  69°;  mean,  74°.  Relative  humidity:  7  a.  m., 
Direction  of  prevailing  wind,  southwest. 


panel  22.    Tem- 
90;  7  p.  m.,  63. 


KESULTS   OF   TESTS.  63 

The  furnace  started  with  a  good,  even  temperature  and  in  about  2 
minutes  considerable  snapping  was  heard,  although  no  cracks 
appeared  either  on  the  face  or  on  the  back  of  the  panel. 

At  5  minutes  it  was  observed  that  the  wall  had  bulged  inward 
toward  the  fire  about  £  inch  and  horizontal  cracks  were  observed  in 
the  mortar  joints  at  the  sides  and  bottom  of  the  panel.  At  10 
minutes  the  wall  had  bulged  If  inches.  At  13  minutes  a  crack 
between  the  sill  and  the  material  in  the  panel  had  developed  to  about 
J  inch  in  width  and  extended  the  entire  length  of  the  panel.  By 
this  time  the  center  of  the  door  had  bulged  1^  inches.  Owing  to  this 
bulging  it  was  feared  that  a  collapse  similar  to  that  of  panel  21  would 
be  repeated.  The  thermocouples  and  thermometers  were  accord- 
ingly removed  from  the  panel.  At  17  minutes  a  block  in  the  center 
of  the  seventh  row  began  to  spall,  starting  at  the  center  of  the  block 
on  the  top  and  running  diagonally  to  the  lower  left  edge.  The  piece 
did  not  fall  off.  At  20  minutes  the  center  of  the  panel  had  bulged 
1J  inches.  At  22  minutes  the  furnace  was  shut  down  for  about  1 
minute,  in  order  that  it  might  be  more  evenly  adjusted.  At  29 
minutes  a  vertical  crack  developed  in  a  block  in  the  seventh  row  on 
the  back  of  the  panel.  Also  a  block  in  the  third  row  on  the  left- 
hand  side  cracked  vertically  on  the  back  near  the  center,  followed 
by  a  vertical  crack  6  inches  from  the  outer  end  and  another  vertical 
crack  4  inches  from  the  inner  end.  These  cracks  did  not  show  on  the 
fired  side,  but  it  is  very  probable  that  they  extended  entirely  through 
the  stone.  At  this  time  the  panel  had  bulged  l|f  inches.  At  33 
minutes  the  seams  at  the  side  of  the  panel  between  the  granite  and 
the  frame  of  the  door  had  opened  to  a  width  of  f  inch  and  extended 
the  entire  height  of  the  wall.  A  vertical  crack  started  in  the  left- 
hand  block  in  the  eighth  row,  about  8  inches  from  the  inner  end, 
developing  on  the  back  of  the  wall.  At  35  minutes  the  wall  had 
bulged  2\  inches.  Small  vertical  cracks  noted  in  nearly  all  the 
pieces  were  gradually  increasing  in  size,  running  vertically.  It  was 
rare  that  one  of  these  cracks  was  directly  over  another,  which  would 
show  that  they  were  due  to  internal  stress  rather  than  to  stress  set 
up  in  the  panel  as  a  whole.  At  40  minutes  the  back  of  the  blocks 
became  too  warm  for  the  hand  to  be  placed  on  them.  At  this  time 
the  wall  had  bulged  2/g-  inches.  At  48  minutes,  on  the  back  of 
the  center  block  in  the  seventh  row,  three  cracks  opened  up  the  entire 
width  of  the  stone,  one  in  the  center  and  the  others  about  6  inches 
from  each  end.  These  cracks  were  about  ^  inch  in  width  and 
apparently  extended  entirely  through  the  piece.  At  50  minutes  a 
thermometer  in  the  center  of  the  wall  was  replaced,  as  it  seemed  that 
the  panel  would  remain  in  the  door. 

At  54  minutes  the  wall  bulged  to  the  extent  of  2f  inches.  At  70 
minutes  the  wall  bulged  to  the  extent  of  2{J  inches.  At  105  minutes 


64  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

no  further  changes  were  observed  in  the  condition  of  the  face,  and  no 
more  cracks  had  developed.  The  wall  at  this  time  had  bulged  2J 
inches.  It  was  again  feared  that  the  wall  would  collapse,  and  a 
picture  was  taken  to  show  the  condition  of  the  cracks  on  the  back. 
At  120  minutes  the  wall  had  bulged  to  the  extent  of  3  inches. 

On  removal  of  the  door  from  the  furnace  there  were  only  three  stones 
that  showed  signs  of  spalling.  One  was  in  the  seventh  row,  center; 
in  another,  in  the  third  row  on  the  right,  the  outer  corner  had  spalled 
off  but  was  in  place;  the  third  instance  of  spalling  was  at  the  upper 
outer  corner  of  the  stone  in  the  third  row  on  the  left  side.  The  con- 
dition of  the  surface  was  about  the  same  as  before  fire  treatment, 
except  that  the  color  had  been  turned  to  a  brownish  blue. 

Before  the  water  was  applied  it  was  impossible  to  observe  any 
cracks  except  those  mentioned.  During  the  first  3  minutes  of  the 
water  application  the  stone  snapped  and  cracked  audibly,  but  none 
of  the  surface  fell  off.  After  this  the  spalling  and  cracking  became 
general,  and  large  pieces  varying  in  depth  from  1  inch  to  1J  inches 
came  off.  About  one-fourth  of  the  surface  of  the  panel  was 
apparently  washed  away. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  24. 

Results. — After  the  water  treatment  the  panel  was  2f  inches  out  of 
plumb.  The  stones  on  the  face  were  of  a  reddish-gray  color  and 
were  very  badly  cracked,  and  the  surface  that  remained  intact  could 
be  easily  crumbled  in  the  fingers.  The  portions  back  about  1  inch 
to  1^  inches  from  the  face  which  had  been  uncovered  were  more  or 
less  hard,  but  badly  split  and  spalled.  The  back  of  the  panel  was 
also  changed  in  color,  but  not  so  much  as  the  face. 

On  taking  down  the  panel  it  was  found  that  all  the  pieces  were  very 
badly  cracked,  both  across  the  stones  and  in  a  plane  parallel  to  the 
face.  The  blocks  were  as  a  rule  broken  into  pieces  about  4  to  8  inches 
long.  The  back  sides  of  the  stones  were  found  to  be  badly  cracked  in 
every  direction,  and  by  gentle  tapping  with  the  hammer  could  be 
broken  into  fragments. 

Plate  XXVIII,  A,  shows  the  face  of  the  panel  after  firing  but 
before  quenching.  Plate  XXVIII,  B,  shows  the  face  after  firing  and 
quenching.  Plate  XXIX,  A,  shows  the  condition  of  the  stone  on 
being  removed  from  the  furnace. 

PANEL  24  (Tile). 

Material. — The  material  composing  panel  24  was  5  by  12  by  12  inch 
partition  tile,  having  three  air  spaces  (fig.  25).  The  tiles  were  laid 
as  a  standard  5-inch  partition  wall  with  about  ^-inch  cement-mortar 
joints,  having  the  core  holes  in  a  vertical  position  and  broken  joints. 
The  face  and  back  were  plastered  with  a  coat,  about  J  inch  thick,  of 


RESULTS   OF   TESTS. 


65 


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FIGURE  24.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  23. 
Temperature:  Maximum,  69°;  minimum,  59°;  mean,  64°.  Relative  humidity:  7  a.m.,  73;  7  p.  m.,  74 
Direction  of  prevailing  wind,  northwest. 

73087— Bull.  370—09 5 


66 


FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 


ordinary  lime  plaster  containing  a  little  hair.  Over  these  two  coats 
was  placed  a  thin  skim  of  plaster  of  Paris,  put  on  as  a  hard  finish  in 
the  usual  way. 

Test. — The  tiles  were  laid  up  on  the  afternoon  of  June  26,  1907, 
plastered  the  morning  of  June  27,  1907,  and  fired  July  1,  1907,  at 
9.27  a.  m.  The  actual  duration  of  the  fire  was  2  hours  and  1  minute, 
after  which  the  panel  was  quenched  for  5  minutes  with  water. 

In  2  minutes  the  surface  coat  of  plaster  on  the  fire  side  fell  off, 
coming  off  in  large  sheets,  about  one-third  of  the  panel  at  a  time.  At 


FIGURE  25.— Sketch  of  partition  tile  used  in  panel  24. 

6  minutes  the  furnace  was  stopped  for  5  minutes  in  order  that  the 
burners  might  be  cleaned  out.  This  5-minute  intermission  was 
deducted  from  the  elapsed  time  of  fire  treatment.  At  10  minutes 
cracks  developed  on  the  back  of  the  panel  horizontally  across  the 
center  at  the  joint  on  the  top  of  the  third  row  of  tiles.  At  15  minutes 
steam  began  to  come  through  the  mortar  around  the  edges  of  the 
panel.  At  18  minutes  a  portion  of  the  lime  plaster  on  the  face,  about 
2  square  feet  in  area  and  about  1  foot  from  the  bottom,  bulged  out 
from  the  tile  about  1  inch.  At  33  minutes  a  crack  developed  on 
the  back  of  the  wall  along  the  bottom  of  the  panel,  extending  the 


U.    S.   GEOLOGICAL    SURVEY 


BULLETIN    370       PLATE    XXIX 


A.     CONDITION  OF  DRESSED   GRANITE  ON  REMOVAL  FROM  PANEL  23. 


B.     FACE  OF  PANEL  24,   PARTITION  TILE,   AFTER  FIRING  AND  QUENCHING. 


RESULTS   OF   TESTS.  67 

entire  width.  The  crack  across  the  center  of  the  door,  before  men- 
tioned, opened  to  the  extent  of  about  ^T  inch.  These  cracks  could 
not  be  observed  in  the  plaster  on  the  fired  side.  At  55  minutes  steam 
began  coming  through  the  joints  around  the  individual  tiles.  This 
was  more  or  less  general  all  over  the  door.  At  60  minutes  a  crack 
developed  horizontally  at  the  joint  of  the  fourth  and  fifth  rows  of 
tiles  and  ran  entirely  across  the  door.  At  95  minutes  diagonal  cracks 
developed  at  the  upper  left-hand  side  of  the  panel  and  ran  about  2 
feet  out  from  the  corner.  At  117  minutes  plaster  on  the  right-hand 
side  of  the  door,  about  halfway  up  the  panel,  bulged  badly,  but  did 
not  fall  off. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  26. 

Results. — On  shutting  off  the  fire  and  undertaking  to  slide  the 
panel  from  the  furnace  the  door  stuck  and  permitted  the  panel  to 
come  out  only  about  halfway.  In  endeavoring  to  pry  the  door 
entirely  open  the  panel  was  very  badly  shaken,  and  the  plaster  coat- 
ing on  the  fired  side,  which  had  been  intact  up  to  this  time,  was 
shaken  off.  Thirty-seven  minutes  elapsed  from  the  time  the  fire 
was  shut  off  until  the  water  was  applied,  this  time  being  spent  in 
trying  to  remove  the  door. 

On  applying  the  water,  only  about  half  of  the  door,  the  right-hand 
side,  was  subjected  to  the  direct  impact  of  the  stream,  though  the 
remaining  portion  was  more  or  less  wet.  The  severe  shaking  which 
caused  the  plaster  to  fall  off  probably  also  cracked  many  of  the 
faces  of  the  tiles  which  were  intact  at  the  time  the  water  was 
applied.  By  the  water  treatment  the  plaster  was  washed  away  on 
the  lower  portion  of  the  back,  and  badly  bulged  at  the  middle  height 
over  the  entire  width  of  the  panel. 

About  65  per  cent  of  the  tiles  that  were  exposed  directly  to  the 
stream  were  washed  away,  while  those  not  so  exposed  were  all  intact, 
with  the  exception  of  two  tiles  at  the  bottom;  they  were,  however, 
badly  cracked. 

After  removing  the  door  from  the  furnace  it  was  found  that  about 
75  per  cent  of  the  faces  of  the  tiles  of  the  entire  panel  had  been  washed 
away  or  would  come  off  by  gently  tapping  with  the  handle  of  a  light 
screw-driver.  The  remaining  25  per  cent  were  badly  cracked,  but 
were  apparently  rigidly  attached  to  the  back  part  of  the  tile.  The 
faces  remaining  in  place  were  very  badly  cracked,  and  could  be  easily 
broken  in  the  hand. 

On  taking  down  the  panel  it  wTas  found  that  none  of  the  tiles  could 
be  taken  out  intact;  they  were  all  cracked  across  the  webs.  The 
back  portion  of  the  webs  and  the  back  faces  of  the  tiles  were  appar- 


68 


FIRE    RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


T/ME 


FIGUBE  26.—  Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  hack  of  panel  24.  Tem- 
perature: Maxi.i.um,  83°;  minimum,  61°;  mean,  72°.  Relative  humidity:  7  a.  m.,  91;  7  p.  m.,  69.  Direc- 
tion of  prevailing  wind,  northwest. 


RESULTS    OF    TESTS.  69 

ently  as  hard  as  before  the  fire  treatment.     Few  cracks  were  observed 
in  this  portion. 

Plates  XXIX,  B,  and  XXX,  A,  show  the  face  and  back  of  the 
panel  after  the  completion  of  the  test. 

PANEL  25  (Building  Stone). 

Material. — Panel  25  consisted  of  five  kinds  of  building  stone,  viz: 
Bedford  limestone  from  Bedford,  Ind.;  limestone  from  Joliet,  111.; 
sandstone  from  Cleveland,  Ohio ;  marble  from  Tait,  Ga. ;  and  granite 
from  the  Thousand  Islands,  Canada. 

The  top  layers  of  the  panel  were  filled  hi  with  hollow  terra-cotta 
tile  in  order  to  make  the  panel  as  light  as  possible.  There  were  two 
courses  of  each  kind  of  stone,  laid  in  cement  mortar  with  broken 
joints.  One  course  of  the  limestone  and  one  of  the  sandstone  was 
laid  on  the  natural  bed;  the  other  had  the  plane  of  the  natural  bed 
exposed  to  the  fire.  In  one  course  the  exposed  face  of  each  block 
was  7 f  inches  long  and  in  the  other  4^  inches.  The  panel  was  backed 
up  with  common  brick  to  make  it  less  liable  to  collapse  during  the 
test. 

Test. — This  test  was  started  at  5.35  p.  m.  July  1,  1907,  and  con- 
tinued for  2  hours.  The  panel  was  cooled  by  a  stream  of  water  at 
57  °  F.  for  5  minutes.  The  bulge  of  the  wall  was  measured  on  the  lime- 
stone header  which  lay  flat  at  the  middle  height. 

In  10  minutes  the  panel  bulged  f  inch.  At  12  minutes  the  sand- 
stone block  in  the  left  center  on  the  second  row  spalled  to  a  depth 
of  about  f  inch  over  the  entire  face,  the  piece  falling  into  the  pit  below. 
At  20  minutes  the  wall  had  bulged  j  J-  inch.  The  center  block  in  the 
seventh  row,  composed  of  limestone,  spalled,  and  a  piece  the  entire 
length  of  the  block  and  about  1  inch  in  depth  fell  off.  At  24  minutes 
small  vertical  cracks  on  the  back  surface  began  to  develop  in  nearly 
all  the  granite  blocks.  At  30  minutes  the. wall  bulged  J  inch,  and 
small  beads  of  water  were  collecting  on  the  back  side  of  the  header 
of  marble.  At  33  minutes  small  vertical  cracks  developed  in  the 
header  of  Bedford  stone.  These  cracks  were  about  8  inches  apart 
and  occurred  in  all  three  pieces  on  the  back  side  of  the  wall.  At  35 
minutes  the  sandstone  blocks  in  the  second  row,  which  had  the  plane 
of  the  natural  bed  parallel  to  the  fired  face,  were  both  very  badly 
spalled,  and  the  stone  on  the  right  side  in  the  second  row  had  crum- 
bled to  a  depth  of  about  3  inches  at  the  end  and  about  1£  inches  at 
the  center.  At  40  minutes  the  limestone  turned  white,  having  be- 
come calcined,  and  showed  fine  irregular  cracks  on  the  surface.  The 
marble  also  showed  signs  of  calcination,  the  surface  becoming  white, 
but  cracks  were  not  visible.  At  50  minutes  the  wall  had  bulged  ]  | 
inch,  and  at  70  minutes  If  inches,  no  apparent  change  in  the  surface 


70  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

of  the  stone  being  noted.  At  120  minutes  the  wall  had  bulged  1T\ 
inches.  After  quenching  the  wall  bulged  J  inch. 

Curves  showing  the  variations  in  temperature  observed  during  the 
test  are  given  in  figure  27. 

Results. — On  removal  of  the  panel  it  was  found  that  the  granite 
was  badly  spalled  and  cracked,  but  the  face  was  still  intact.  The 
faces  of  the  limestone  were  intact  but  very  white,  except  the  piece 
which  fell  out,  before  noted.  The  marble  was  very  badly  calcined 
and  the  face  chalky  white;  no  cracks  were  visible,  and  the  entire  face 
was  intact.  The  Bedford  limestone  was  badly  cracked  and  the  face 
considerably  calcined.  The  sandstone  showed  deep  seams  in  the 
pieces  that  were  lying  on  their  natural  bed,  and  the  other  stones  were 
more  or  less  spalled. 

During  the  application  of  the  water  the  granite,  limestone,  and 
Bedford  stone  cracked  and  their  faces  washed  away  considerably. 
The  entire  surface  of  the  granite  was  washed  away  about  J  inch; 
three  of  the  stones  were  badly  cracked,  and  the  faces  fell  off  to  a  depth 
of  about  2  inches.  The  limestone  was  calcined  to  a  depth  of  about 
\\  inches,  and  most  of  the  faces  had  fallen  off  to  about  this  depth. 
The  stones  were  cracked  into  small  fragments  (2  to  3  inches)  by 
cracks  which  ran  entirely  through  the  pieces.  This  was  true  also  of 
the  Bedford  limestone,  but  the  calcining  and  spalling  was  only  from 
|  inch  to_lj  inches  deep.  The  marble  washed  away  under  the  water 
treatment  from  1  inch  to  1J  inches  in  depth,  and  the  surface  had  a 
crystalline  and  very  rough  appearance ;  no  cracks  were  visible  in  the 
pieces  which  had  the  7 f -inch  face  exposed.  The  pieces  with  the 
4J-inch  face  exposed  were  cracked  back  from  the  face,  the  cracks 
being  nearly  vertical  and  more  or  less  irregular.  The  sandstone 
washed  away  to  a  depth  of  about  J  inch;  the  surfaces  left  were  hard 
and  had  turned  a  dark  red.  The  stones  lying  on  the  natural  bed 
were  not  washed  away  as  much  as  the  others,  but  irregular  vertical 
cracks  ran  all  through  them,  and  the  seams  had  opened  up.  The 
pieces  laid  with  the  bedding  planes  on  edge  were  badly  cracked,  and 
the  water  washed  them  away  from  \  inch  to  1  \  inches  in  depth.  The 
surfaces  were  rough  and  of  a  reddish  color  and  were  very  badly 
cracked. 

On  taking  down  the  panel  the  granite  was  found  to  be  broken  into 
small  pieces  from  6  to  8  inches  in  length,  the  cracks  running  back 
from  the  fired  face.  The  limestone  came  out  in  small  pieces,  having 
broken  along  nearly  vertical  and  horizontal  lines.  The  faces  to  a 
depth  of  about  1  inch  to  1J  inches  usually  cracked  away  from  the 
back  portion.  The  marble  was  found  to  break  into  pieces  about  4  to 
6  inches  in  length;  the  cracks,  which  were  not  visible  before  the 
blocks  were  removed  from  the  panel,  were  more  or  less  irregular,  but 
usually  had.  a  general  vertical  direction.  The  marble  lying  with  the 


EESULTS  OF  TESTS. 


71 


FIGURE  27.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  25.  Tem- 
perature: Maximum,  83°;  minimum,  61°;  mean,  72°.  Relative  humidity:  7a.m.,  91;  7  p.m.,  69.  Direc- 
tion of  prevailing  wind,  north  west. 


72  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

4J-inch  face  exposed  was  cracked  in  like  manner.  The  Bedford  lime- 
stone acted  like  the  other  limestone,  except  that  the  pieces  were 
somewhat  larger. 

The  sandstone  was  badly  cracked  along  the  stratification  planes 
and  also  broke  into  small  pieces  by  cracking  perpendicularly  to  the 
bed.  The  blocks  lying  with  the  natural  bed  parallel  to  the  fired  face 
cracked  more  or  less  irregularly,  and  their  faces  were  entirely  gone. 
Those  on  the  natural  bed,  however,  except  for  perhaps  i  or  J  inch 
which  had  washed  away,  were  intact,  but  split  and  cracked. 

Plates  XXX,  J5,  and  XXXI,  A,  show  the  face  of  the  panel  before 
and  after  testing.  Plate  XXXI,  B,  shows  the  back  after  testing. 

PANEL  26  (Building  Stone). 

Material. — Panel  26  consisted  of  blocks  of  Georgia  marble  laid 
with  broken  joints  in  cement  mortar  with  4-inch  and  ?i-inch  faces 
exposed,  as  shown  in  Plate  XXXII,  A.  The  lower  part  of  the  panel 
was  backed  with  common  brick,  and  the  upper  portion  was  laid  up 
with  partition  tile  in  order  to  make  the  panel  as  light  as  possible. 

Test. — The  test  was  started  at  9.47  a.  m.  July  6,  1907,  and  firing 
continued  for  2  hours  and  1  minute.  The  panel  was  cooled  by  water 
at  61°  F.  for  5  minutes.  A  fairly  uniform  fire  was  obtained,  the  top 
being  slightly  hotter  than  the  bottom  and  the  center  of  the  panel. 
The  bulging  was  measured  at  the  center  of  the  panel  on  the  second 
stretcher  of  marble. 

In  7  minutes  cracks  developed  along  the  edge  of  the  panel  on  both 
sides.  At  10  minutes  the  panel  had  bulged  toward  the  fire  about 
J  inch.  At  this  time  control  of  the  furnace  was  lost  and  the  tempera- 
tures ran  too  high  for  three  or  four  minutes.  At  75  minutes  vertical 
cracks  developed  on  the  back  of  the  lower  left-hand  stone,  one  about 
3  inches  from  the  edge  and  one  in  the  center.  A  vertical  crack,  start- 
ing at  the  top  and  running  down  to  the  bottom,  showed  near  the 
middle  of  the  center  stone  of  the  same  row.  At  120  minutes  the,  wall 
had  bulged  1^|  inches.  After  quenching  the  bulging  was  1T\  inches. 

Curves  showing  the  variations  of  temperature  throughout  the  test 
are  given  in  figure  28. 

Results. — When  the  door  was  removed  from  the  furnace  the  surface 
appeared  to  be  smooth,  but  very  chalky.  On  applying  water  the 
surface  slacked  for  about  a  minute  or  two,  and  gradually  washed 
away;  then  it  became  very  rough,  showing  the  crystalline  structure 
of  the  rock,  and  washed  away  to  a  total  depth  of  \  inch  to  If  inches. 
After  cooling,  the  surface  was  found  to  be  very  rough  and  the  crys- 
talline structure  showed  very  plainly.  Dark  streaks  in  the  marble 
withstood  fire  and  water  better  and  stood  out  beyond  the  general 
surface.  The  narrow  faces  were  apparently  more  badly  damaged, 
being  cracked  back  from  the  fired  face  into  pieces  from  4  to  18  inches 


A      •  .•::•::  v 
,  '-•  :  :• ;  •.„• 


RESULTS   OF   TESTS. 


73 


^$^§s§§! 

T/ME  //V  M/NUTES 

FIGURE  28. — Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  hack  of  panel  26.  Tem- 
perature: Maximum,  79°;  minimum,  65°;  mean,  72°.  Relative  humidity;  7  a.  m.,  93;  7 p,  m.,  86.  Direc- 
tion of  prevailing  wind,  north. 


74  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

in  length.  The  pieces  with  7^-inch  face  exposed  showed  very  few 
visible  cracks,  but  some  of  them  were  spalled,  with  the  corners  and 
edges  washed  away.  However,  on  taking  the  panel  down  it  was  found 
that  all  the  pieces  of  stone  were  cracked  into  lengths  of  about  4  to  6 
inches,  the  cracks  being  vertical  and  running  back  through  the  entire 
stone.  The  4-inch  layers  against  the  sill  at  the  bottom  of  the  panel 
were  less  affected  than  any  others,  but  were  somewhat  protected 
because  the  brick  projected  about  li  inches  beyond  them. 

Plate  XXXII,  A,  shows  the  face  of  the  panel  before  firing;  Plate 
XXXII,  B,  shows  the  face  of  the  panel  after  firing,  but  before  the 
application  of  water;  Plate  XXXIII,  A,  shows  the  effect  of  the  water; 
and  Plate  XXXIII,  B,  shows  the  back  of  the  panel  after  firing  and 
quenching. 

PANEL  27  (Building  Stone). 

Material. — Panel  27  consisted  of  blocks  of  Niagaran  magnesian  lime- 
stone with  4-inch  and  7f-inch  faces  and  was  built  and  backed  as  in 
panel  26. 

Test.— The  test  was  started  at  2.35  p.  m.  July  8,  1907,  and  firing 
was  continued  for  2  .hours  and  30  seconds.  The  panel  was  cooled  by 
water  at  63°  F.,  applied  for  5  minutes.  The  furnace  showed  a  good 
uniform  temperature,  slightly  hotter  at  the  bottom.  The  bulging  of 
the  wall  was  measured  on  the  second  header  of  limestone  at  the  center. 
This  was  not  quite  the  center  of  the  panel,  but  it  was  deemed  advis- 
able to  take  it  there  rather  than  on  the  brick,  which  could  not  be 
rigidly  attached  to  the  face. 

In  4  minutes  the  surface  of  the  blocks  on  the  fired  side  cracked 
until  several  pieces  from  the  7f-inch  courses  fell.  At  10  minutes  the 
wall  had  bulged  toward  the  fire  -^  inch,  and  at  20  minutes  J  inch. 
At  27  minutes  vertical  cracks  showed  through  the  center  and  also 
the  lower  headers  on  the  back  side.  These  cracks  were  near  the 
middle  of  the  center  blocks.  Two  cracks  also  developed  about  equal 
distances  from  the  end  in  the  upper  header  on  the  right-hand  side. 
At  the  end  of  30  minutes  the  furnace  was  shut  down  for  14  minutes 
in  order  to  clean  the  burners,  into  which  pieces  of  the  wall  had  fallen. 
This  interval  (14  minutes)  was  deducted  from  the  elapsed  time,  so 
that  the  actual  firing  time  was  2  hours.  At  40  minutes  the  panel 
had  bulged  f  inch.  The  right-hand  block  in  the  seventh  row  cracked 
back  to  a  depth  of  about  2  inches,  and  a  piece  the  entire  length  of  the 
block -fell  off.  The  left  block  in  the  bottom  row  acted  in  the  same 
manner,  a  piece  about  two-thirds  of  the  length  of  the  block  and  2 
inches  in  depth  falling  out.  At  50  minutes  the  wall  bulged  \  |  inch, 
and  at  70  minutes  1TV  inches.  At  75  minutes  longitudinal  cracks 
appeared  on  the  fired  face  of  the  left-hand  large  block  of  the  sixth 
row,  also  the  center  block  in  the  third  row,  and  the  left-hand  block 


U.   S.   GEOLOGICAL   SURVE 


BULLETIN    370       PLATE    XXXIII 


A.     FACE  OF  PANEL  26,  DRESSED   MARBLE  WITH  BRICK  BACKING,  AFTER 
FIRING  AND  QUENCHING. 


B.     BACK  OF  PANEL  26,   DRESSED   MARBLE  WITH  BRICK  BACKING,  AFTER 
FIRING  AND  QUENCHING. 


RESULTS    OF   TESTS.  75 

in  the  second  row.  The  right-hand  block  in  the  fifth  row  spalled  all 
over  the  face,  starting  from  the  center  and  running  toward  the  edges. 
This  was  also  noticed  on  the  right-hand  block  in  the  same  row.  The 
fire  on  the  right-hand  side  of  the  furnace  was  considerably  stronger 
than  on  the  left-hand  side,  where  the  burners  were  clogged  by  pieces 
of  the  wall  that  had  spalled  off.  At  80  minutes  the  panel  had  bulged 
1£  inches,  and  at  120  minutes  the  bulging  amounted  to  1J  inches. 
After  cooling  bulging  amounted  to  ^f  inch. 

Curves  showing  the  variations  of  temperature  throughout  the  test 
are  given  in  figure  29. 

Results. — On  removing  the  panel  from  the  furnace  it  was  found  to 
be  of  a  white,  chalky  color,  and  all  the  blocks  were  more  or  less  cracked 
irregularly.  On  applying  the  water  the  surface  was  washed  away, 
the  water  being  milky  white  as  it  came  away.  The  washing 
on  the  right-hand  side  of  the  panel  was  from  J  to  f  inch  deep,  and 
about  |  inch  deep  on  the  left-hand  side.  The  stone  snapped  and 
cracked  under  the  application  of  the  water,  but  no  pieces  flew  off. 
A  few  of  the  pieces  were  washed  away. 

After  the  door  was  cooled  it  was  found  that  on  the  right-hand  side 
of  the  furnace  the  blocks  were  calcined  to  a  depth  of  about  f  to  1  inch, 
and  were  of  a  whitish  color  to  this  depth.  The  surface  was  soft  and 
chalky,  and  the  blocks  were  all  cracked  into  small  pieces,  about  4  to 
6  inches  square,  most  cracks  being  in  the  vertical  and  horizontal 
planes.  The  faces  could  be  chipped  off  in  irregular  layers,  but  the 
body  of  each  block  was  cracked  into  small  pieces  from  4  to  6  inches 
square.  The  surface  was  quite  hard,  although  it  flew  to  pieces  when 
tapped  with  a  hammer. 

Plate  XXXIV,  A,  shows  the  face  of  the  panel  after  firing  and  quench- 
ing; Plate  XXXIV,  B,  shows  the  back  after  firing  and  quenching; 
Plate  XXXV,  B,  shows  the  appearance  of  the  blocks  when  removed 
from  the  panel. 

PANEL  28  (Building  Stone). 

Material. — Panel  28  consisted  of  blocks  of  Bedford  limestone  with 
4-inch  and  7f-inch  faces,  and  was  built  and  backed  as  in  panels  26 
and  27. 

Test.— The  test  was  started  at  3.02  p.  m.,  July  9,  1907,  and  firing 
was  continued  for  2  hours  and  45  minutes.  The  panel  was  cooled 
by  water  at  64°  F.,  applied  for  5  minutes.  The  heat  in  the  furnace 
was  fairly  uniform,  being  perhaps  a  little  greater  on  the  right-hand 
side. 

In  10  minutes  the  wall  bulged  toward  the  fire  |  inch  at  the  center, 
the  measurement  being  taken  at  the  second  header.  No  cracking 
was  observed  up  to  this  time.  At  18  minutes  the  surface  began  to 
turn  a  rather  chalky  color,  but  no  cracks  were  noticed,  nor  was  any 


76 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


FIGURE  29. — Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  27.  Tern. 
perature:  Maximum,  85°;  minimum,  72°;  mean  78°.  Relative  humidity:  7  a.m.,  67;  7  p.m.,  58.  Direc- 
tion of  prevailing  wind,  west. 


U.    8.   GEOLOGICAL   SURVEY 


BULLETIN    370      PLATE    XXXIV 


FACE  OF  PANEL  27,  DRESSED  LIMESTONE  WITH   BRICK  BACKING,  AFTER 
FIRING  AND  QUENCHING. 


B.     BACK  OF  PANEL  27,  DRESSED  LIMESTONE  WITH  BRICK  BACKING,  AFTER  FIRING  AND 

QUENCHING. 


RESULTS   OF   TESTS.  77 

spalling  evident.  At  20  minutes  the  wall  bulged  Jf  inch.  A  ver- 
tical crack  was  noticed  about  11  inches  from  the  outer  edge  on  the 
back  of  the  right-hand  stone  of  the  lower  tier.  This  was  not  visible 
on  the  fired  side.  At  30  minutes  the  panel  had  bulged  iuward  about 
1  inch.  At  45  minutes  the  stone  in  the  center  row  on  the  right-hand 
side  cracked  vertically  at  the  center.  At  70  minutes  the  wall  bulged 
1J  inches,  at  80  minutes  Ij3g  inches,  and  at  110  minutes  1J  inches, 
but  no  cracking  or  spalling  was  observed  up  to  this  time. 

Curves  showing  the  variations  in  temperature  throughout  the  test 
are  given  in  figure  30. 

Results. — The  panel  on  removal  had  a  white,  chalky  color,  but  no 
cracks  or  indications  of  spalling  were  in  evidence.  Oh  the  applica- 
tion of  water  the  color  changed  to  a  dark  grayish  blue,  and  the  sur- 
face washed  away  about  }  inch  during  the  treatment. 

Cracks  developed  rapidly  in  all  the  pieces  during  the  first  2  minutes, 
but  the  surface  remained  intact.  During  the  next  3  minutes  pieces 
of  various  dimensions,  from  }  inch  to  1J  inches  thick,  fell  off  the 
panel  and  at  the  end  of  the  treatment  fully  50  per  cent  of  the  surface, 
varying  in  thickness  from  f  to  3  inches,  had  fallen  away.  The  remain- 
ing surface  was  badly  cracked  and  could  be  broken  off  from  a  depth 
of  f  inch  to  li  inches  by  gently  tapping.  This  surface  was  rough 
and  pitted,  and  also  showed  considerable  calcination.  On  taking 
down  the  panel  it  was  found  that  all  the  blocks  were  broken,  and 
that  they  crumbled  easily  on  the  fired  side,  the  back  being  very  hard. 
The  stones,  on  removal  from  the  door,  fell  mostly  into  pieces  from 
4  to  12  inches  in  length,  but  some  were  broken  into  many  little 
cubes  (2  to  3  inches). 

Plate  XXXV,  A,  shows  the  face  of  the  panel  after  firing,  and  Plate 
XXXVI,  A,  shows  its  appearance  after  applying  water.  Plate 
XXXVI,  B,  indicates  the  appearance  of  the  blocks  after  removal 
from  the  furnace  and  gives  an  idea  of  the  damage  wrought. 

PANEL  29  (Sand-Lime  Brick). 

Material. — Sand-lime  bricks  of  medium  quality  were  used  in 
panel  29.  They  were  almost  white,  but  had  a  slightly  brownish 
tinge  and  a  very  few  white  lime  particles  scattered  through  them. 
The  corners  and  edges  were  square,  the  faces  smooth,  and  the  bricks 
uniform  in  size.  The  material,  however,  could  be  rubbed  from  the 
faces  with  the  fingers,  and  when  two  bricks  were  rubbed  together  the 
surfaces  were  abraded  considerably.  Table  14  gives  the  physical 
properties  and  the  strength  tests  of  the  bricks  used. 

The  panel  was  composed  of  the  sand-lime  bricks  backed  with 
common  clay  bricks  and  laid  in  cement  mortar  as  a  standard  8-inch 
wall,  with  headers  every  sixth  row.  A  small  portion  of  the  back 
wall,  at  the  center,  was  composed  of  sand-lime  bricks. 


78 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


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I 


Ai 


FACE 


z 


2.3.4.5 


900 


$ — '•* 


700 


FURNACE 


400 
300 
200 
/00 


/zoo 


/ooo 

900 
800 


700 


600 


WATER   PYROMETER 


SOO 


300 


70 


BACK    OF   PANEL 


so 


30 

26 


a 


FIGURE  30.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  28.  Tem- 
perature: Maximum,  77°;  minimum,  69°;  mean,  73°.  Relative  humidity:  7  a.  m.,  79;  7  p.  m.,  84.  Direc- 
tion of  prevailing  wind,  east. 


U.    S.    GEOLOGICAL    SURVEY 


BULLETIN    370       PLATE    XXXV 


A.     FACE  OF  PANEL  28,  DRESSED  LIMESTONE,  AFTER  FIRING  AND  BEFORE 
QUENCHING. 


B.     DRESSED  LIMESTONE  AFTER  REMOVAL  FROM  PANEL  27. 


U.    S.    GEOLOGICAL   SURVEY 


BULLETIN    370       PLATE   XXXVI 


A.     FACE  OF  PANEL  28,   DRESSED  LIMESTONE,  AFTER  FIRING  AND 
QUENCHING. 


B.     BLOCKS  OF  PANEL  28,   DRESSED  LIMESTONE,  AFTER  REMOVAL  FROM   FURNACE. 


RESULTS   OF    TESTS.  79 

Test. — The  test  was  made  on  July  11,  1907,  and  the  firing  was  con- 
tinued for  2  hours.  The  panel  was  cooled  by  water  at  61°  F.,  ap- 
plied for  5  minutes  and  20  seconds.  A  fairly  uniform  furnace  tem- 
perature, slightly  cooler  at  the  bottom  at  the  start,  was  obtained. 

In  10  minutes  the  wall  had  bulged  at  the  center  about  J  inch. 
The  bulging  was  measured  at  the  center  of  the  third  header  from  the 
bottom.  At  20  minutes  the  wall  bulged  about  \  inch,  no  apparent 
change  in  the  surface  being  noted  up  to  this  time.  At  30  minutes 
the  wall  bulged  \\  inch.  It  was  noted  that  water  was  forced  back 
through  one  of  the  bricks  in  the  fourth  header  near  the  center  of  the 
wall.  There  was  a  small  crack  on  the  surface  of  the  brick,  appar- 
ently due  to  shrinkage  or  improper  molding.  At  40  minutes  the  wall 
had  bulged  to  the  extent  of  f  inch.  The  surface  of  the  bricks  on  the 
fired  side  had  begun  to  have  a  chalky  appearance,  as  if  calcination 
of  the  lime  had  taken  place.  At  60  minutes  the  wall  had  bulged 
inward  to  the  extent  of  1T\  inches,  and  at  120  minutes  1T5^  inches. 
After  cooling  the  wall  bulged  toward  the  fire  \\  inch. 

Curves  showing  the  variations  of  temperature  throughout  the  test 
are  given  in  figure  31. 

Results. — On  removal  of  the  door  from  the  furnace  the  surface  of 
the  panel  showed  no  signs  of  having  spalled,  but  was  chalky  white 
and  looked  very  soft.  On  the  application  of  water  the  surfaces 
washed  away  from  J  inch  in  a  few  places  to  about  1 J  inches  in  others. 
The  surfaces  of  the  majority  of  the  bricks  in  the  panel  were  washed 
away  to  the  extent  of  f  to  J  inch. 

After  the  wall  had  cooled  it  was  found  that  the  surfaces  of  the 
bricks  were  very  rough  and  were  covered  with  small  irregular  cracks 
extending  back  about  1  inch  to  1|  inches.  There  were  also  small 
pocklike  marks  in  nearly  every  brick,  apparently  where  lumps  of 
lime  had  washed  away.  In  one  or  two  places  small  lumps  of  sand 
were  also  found.  The  remaining  portions  of  the  brick  on  the  faces 
were  soft  and  crumbled  very  easily  in  the  fingers.  The  back  portions 
were  nearly  as  hard  as  before  the  fire  treatment.  When  the  bricks 
became  thoroughly  dry,  the  surfaces  were  considerably  harder.  The 
header  bricks  were  found  to  be  cracked  and  crumbled  back  to  a 
depth  of  about  1J  inches,  the  remainder  being  apparently  hard  and 
unaffected. 

On  taking  down  the  panel  it  was  found  that  the  stretcher  bricks 
composing  the  fired  side  were  cracked  back  vertically  from  the  fired 
face,  usually  in  two  or  three  pieces.  The  face  was  taken  down  with 
great  care  and  about  20  per  cent  of  the  bricks  were  removed  intact, 
but  nearly  all  failed  in  handling,  breaking  into  two  or  three  pieces. 

The  sand-lime  bricks  that  were  laid  in  the  back  courses  were  appar- 
ently not  affected  by  the  heat  and  were  removed  with  little  loss,  but 


80 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


/ooo 

900 
800 
700 
600 
SOO 
4OO 
SOO 
SOO 
/OO 

6 
/ooo 


£ ! 


«^1 


P" 


£ 

JM   700 

.     60O 


FURNACE 


300 
800 
100 


900 
800 
700 

eoo 
soo 

4OO 
7O 
60 
SO 
40 
SO 

e& 


WATER   PYROMETER 


/o 


FIGURE  31.— Diagram  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  29.  Tem- 
perature: Maximum,  71°;  minimum,  63°;  mean,  C7°.  Relative  humidity:  7  a.  m.,  87;  7  p.  m.;  86.  Direc- 
tion of  prevailing  wind,  north. 


RESULTS   OF   TESTS.  81 

the  mortar  stuck  to  the  bricks,  and  they  were  hard  to  clean.  There 
was  a  tendency  for  the  surfaces  of  the  bricks  to  come  away  with  the 
mortar  as  it  was  chipped  off. 

Plate  XXXVII,  A,  shows  the  face  of  the  panel  after  firing;  Plate 
XXXVII,  B,  shows  it  after  the  application  of  water. 

PANEL  30  (Tile). 

Material. — The  material  composing  panel  30  was  5  by  12  by  12 
inch  partition  tile,  having  three  air  spaces  (fig.  25).  The  tiles  were 
laid  in  cement  mortar,  with  about  ^-inch  joints,  as  a  5-inch  partition. 
They  were  laid  with  the  core  holes  vertical  and  the  joints  broken.. 
The  face  of  the  panel  was  plastered  with  ordinary  lime  plaster  con- 
taining a  little  plaster  of  paris  and  also  some  hair,  the  coating  being 
about  %  inch  thick.  Xo  hardening  coat  was  put  on  this  panel,  as  it 
had  been  found  seriously  to  interfere  with  the  operation  of  the  furnace 
by  falling  into  the  burners. 

The  tiles  were  sprinkled  before  laying,  as  they  were  so  dry  that 
they  took  the  moisture  from  the  mortar  too  rapidly.  The  tiles  were 
laid  the  morning  of  July  12;  the  fired  face  was  plastered  the  afternoon 
of  the  same  day  and  the  back  face  the  morning  of  July  13,  and  the 
panel  was  shoved  into  the  furnace  to  protect  it  from  the  weather  on 
the  afternoon  of  the  13th. 

Test.— The  test  was  started  at  10.38  a.  m.  on  July  16,  1907,  and 
firing  was  continued  for  2  hours  and  30  minutes.  The  panel  was 
cooled  for  5  minutes  by  water  at  62°  F.  A  good  uniform  fire  was 
obtained. 

As  soon  as  the  fire  was  started  the  wall  began  to  snap,  and  small 
pieces  of  plaster  cracked  off  on  the  fired  side. 

At  the  expiration  of  4  minutes  the  furnace  was  shut  down  for  6J 
minutes,  in  order  to  remove  plaster  that  had  fallen  into  the  burners. 
About  one-third  of  the  plaster  had  fallen  off  just  prior  to  this  period, 
and  during  the  cleaning  of  the  burners  all  loose  plaster  that  had 
bulged  away  from  the  panel  and  not  fallen  off  was  removed,  in  order 
to  avoid  the  necessity  of  shutting  down  again.  At  9  minutes  a 
horizontal  crack  developed  on  the  back  between  the  face  and  the 
second  row  of  tiles.  A  similar  crack  also  developed  between  the 
third  and  fourth  rows.  These  cracks  extended  clear  across  the  panel. 
At  10  minutes  the  wall  had  bulged  inward  about  \  inch,  the  bulging 
being  measured  at  the  center  of  the  fourth  row  of  tiles.  At  12  min- 
utes a  horizontal  crack  developed  between  the  second  and  third  rows 
of  tiles,  extending  across  the  door.  At  14  minutes  a  vertical  crack 
developed  at  the  edge  along  the  left  side  of  the  panel,  starting  at  the 
top  and  running  down  to  the  joint  between  the  fourth  and  fifth  rows 
of  tiles,  and  then  extending  horizontally  &CJ:QSS  the  panel..  At  17 

73087— Bull.  370—09 6 


82  FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 

minutes  steam  began  to  come  through  the  lower  cracks  and  along  the 
sides  of  the  panel,  and  the  moisture  began  to  come  through  the 
plaster  on  the  back  opposite  the  joints  in  the  tiles.  At  19  min- 
utes diagonal  cracks  from  the  upper  right-hand  corner  began  to  show 
through  the  plaster  and  to  run  off  across  the  door.  A  vertical  crack 
developed  at  the  bottom  on  the  left-hand  side  one  tier  out  from 
the  edge  and  extended  up  to  the  joint  between  the  first  and  second 
rows,  and  then  ran  diagonally  across  the  panel  toward  the  edge.  At 
20  minutes  the  wall  had  bulged  f  inch.  At  23  minutes  all  the  re- 
maining plaster  on  the  fired  side,  except  a  few  small  areas  (3  to  4 
square  inches)  scattered  about  the  surface,  came  off,  and  the  furnace 
was  shut  down  for  3  minutes  to  clean  the  burners.  This  time  (3  min- 
utes) and  that  of  the  previous  shut  down  (6^  minutes)  were  deducted 
from  the  elapsed  running  time  of  the  test.  At  30  minutes  a  series 
of  small  diagonal  cracks  developed  at  the  top  of  the  fourth  row  of 
tiles  on  the  left-hand  side.  The  cracks  were  from  3  to  4  inches  long 
and  about  1  inch  apart,  and  extended  from  about  6  inches  off  the 
edge  toward  the  center  for  a  distance  of  about  2  feet.  At  40  minutes 
the  wall  had  bulged  f  inch.  At  44  minutes  the  tile  on  the  right-hand 
side  of  the  fourth  row  cracked  horizontally  on  the  fired  side,  the  crack 
occurring  about  2  inches  from  the  lower  edge  and  extending 
entirely  across  the  tile.  The  edges  of  the  crack  bulged  outward  and 
were  more  or  less  irregular.  At  60  minutes  the  wall  bulged  ^J-  inch. 
By  this  time  small  more  or  less  irregular  cracks  had  developed  in 
both  vertical  and  horizontal  directions  in  the  plaster  on  the  back 
side  of  the  panel  around  each  tile.  At  120  minutes  the  wall  bulged 
f  inch.  After  cooling  there  was  a  permanent  bulging  of  J  inch  in  the 
panel. 

Results. — When  the  panel  was  removed  from  the  furnace,  the  plaster 
was  practically  gone.  Around  the  bottom  edge  and  on  the  upper 
right-hand  and  left-hand  corners  there  were  small  pieces,  and  a  small 
patch  on  the  second  and  third  rows  was  still  intact.  The  tiles  were 
more  or  less  cracked,  especially  the  ones  that  were  entirely  free  from 
mortar;  that  is,  the  second  tile  from  the  right-hand  side  in  the  third  row 
and  the  tile  nearest  the  right-hand  side  in  the  second  row;  also  a  small 
corner  of  the  second  tile  on  the  right-hand  side  of  the  bottom  row  had 
cracked  off.  Cracks  could  not  be  observed  in  the  other  tiles,  but  they 
had  a  thin  layer  of  plaster  still  sticking  to  them,  which  prevented 
examination. 

On  applying  water  the  tiles  cracked,  and  after  the  first  minute  the 
faces  began  to  fall  off.  At  the  end  of  5  minutes  about  55  per  cent 
of  the  faces  of  the  tiles  was  washed  away.  This  occurred  on  the  lower 
and  right-hand  side  of  the  panel.  The  tiles  on  the  upper  left-hand 
side  still  were  in  place.  These  tiles  that  were  in  place,  however,  were 
found  to  be  cracked  loose  from  the  webs  near  the  fired  side,  and  the 


RESULTS   OF   TESTS.  83 

faces  were  all  cracked,  the  cracks  running  irregularly  and  a  few  of 
them  extending  through  the  face.  A  few  of  the  faces  of  the  tiles  also 
spalled  off  to  a  depth  of  TV  to  i  inch. 

After  the  wrall  had  cooled  it  was  found  that  about  55  per  cent  of  the 
tiles  that  remained  in  place  could  be  lifted  off.  Those  that  did  remain 
in  place  were  cracked  from  the  webs,  and  the  faces  were  cracked  but 
were  apparently  still  rigidly  attached.  The  portions  of  the  web 
remaining  attached  to  the  backs  and  the  backs  themselves  were 
apparently  hard  and  free  from  cracks.  The  fired  faces,  however, 
crumbled  easily  in  the  hands.  The  plaster  on  the  back  wall  was 
forced  off,  exposing  about  five  tiles  at  the  bottom  of  the  wall;  and 
although  over  the  remainder  of  the  wall  tho  plaster  remained  intact 
it  was  badly  bulged,  and  water  had  come  through  all  the  joints. 

Curves  showing  the  variations  in  temperatures  throughout  the  test 
are  given  in  figure  32. 

Plate  XXXVIII,  A,  shows  the  face  of  the  panel  after  firing  and 
before  water  was  applied;  Plate  XXXVIII,  B,  the  face  of  the  panel 
after  quenching;  Plate  XXXIX,  A,  the  face  of  the  panel  after  all 
loose  pieces  had  been  removed;  and  Plate  XXXIX,  B,  the  back  of  the 
panel  after  firing  and  quenching. 


84 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


T/ME/Af  W NOTES 

— Pia^rarn  showing  temperature  conditions  in  the  furnace  and  on  the  back  of  panel  30. 


RESULTS   OF   TESTS. 
TABLES. 


85 


TABLE  1. — Panel  1 — Results  of  compression  tests  made  on  portions  of  one-piece  double- 
air-space  mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  ".  
2  

(            2 
•7 

{      ! 

f            4 
\           3 

'836' 

1,780 

2 

918 

• 

1,754 

3 
3 
3 

2 

1,240 

2 

584 

3  

1,594 
922    

746 

1,263 

2 

578 

Average  .  . 

NSo           1,709 

752           1,  140 

I 

581 

MEDIUM  BLOCKS. 


f            4 

2,337 

2 

1,200 

1                               898 

1  V           2 

883 

o                                                 1               1 

1,963 

1 

I        1,533 

1                               770 

2  \            2 

1,457 

2           462 

o                        f      .  i 

2,245 

2 

1,511 

1    645 

3  {            2 

1,643 

2 

831  ! 

\.veratro 

1  328 

2  182 

831           1  415 

462  1              771 

1                1 

WET  BLOCKS. 


1 

x                       \       1  

1,634 

1 

2,042 

803 

\           2          793 
2                                     ?            1    

-  \        i     1,101 

1.940 

5 

897 

1,365 

&53 

950 

/            1    

2.100 

4 

1,670 

1,045 

6  \           o           746 

275 

Average  .  .             .                   880 

1,891 

897 

1,692 

376 

933 

FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  2. — Panel  2 — Results  of  compression  tests  made  on  portions  of  one-piece  single- 
air-space  mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

f           2 

I 
1 

I           3 

1,702 

2 
2 
2 
2 
2 
3 

535 

2 

2 
3 

2 

"~53i~ 

814 

2 

1,338 

"i,'ioi' 

1,948 

651 

776 

548 

3 

1,299 

712 

830 

327 

Average  

608 

595 

2           344    

1,016 

1,650 

653 

714 

401 

681 

MEDIUM  BLOCKS. 


I/       2 

1,302 

2 

1,190 

1 

683 

1                          * 

'  {       I 

1,355 

1,758 

2 
2 

768 
""797" 

933 

1 
2 

408 

746 

3  {  3- 

955 

2 
1 

870 

1,111 

2 
2 

555 

713 

Average  ' 

971 

1  530 

812 

1  078 

482 

714 

WET  BLOCKS. 


1  

{     • 

2  205 

2,808 

2 

1,013 

2 

645 

2 

}       5 

2,049 

3 

1,030 

2 

615 

I            2 

1,876 

2 

684 

1 

469 

1            2 

2,318 

2 

1,222 

2 

669 

\           2 

1,767 

2 

856 

1 

319 

Average  

1,949 

2  391 

779 

1  088 

482 

643 

RESULTS   OF   TESTS. 


87 


TABLE  3. — Panel  3 — Results  of  compression  tests  made  on  portions  of  one-piece  double- 
air-space  mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 

[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port-     4  parts  sand  to  1  of  Port- 
land cement.                          land  cement. 

1 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

1 
Average 
strength. 
No.  of 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

pieces 
crushed.     Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

f            4 
\           2 
1            2 

1,833 

3   

949 

2 

|             502 

2  

1,841 

2 

853 

2          552 
2 

2 

493 

3.  

i      \ 

"i,"2ii" 

1,047 

925 

"" 

1,165 

1,874 

552 

909 

493 

502 

MEDIUM  BLOCKS. 


i     2 

2  570 

1 
2 

2,070       2  990 

1  

o 

1  OAK 

2 

1  163 

2 

/     3 

3,128 

I 

2,013       2  478 

\     2 
t     2 

^1,105 

2,385 

3 

1,712       4  827 

3  

{     % 

9 

923 

I     « 

1  507 

2  694 

1,155 

1,932  464       765 

WET  BLOCKS. 


i 
{2 

2  219 

2 

i 

1" 

o 

795 

•s 

' 

2  512 

2 

1,381    '  

2  fl 

{                           0 

2 

966                                                      ' 

}            2 

2,ooU 

2  699 

2 

1  487 

3  «  

{            I 

1,932 

2 

992    

1  957 

2  477 

918           1,494    

o  Blocks  of  8  parts  sand  to  1  of  Portland  cement  were  destroyed  in  transit  from  Underwriters'  Laboratories 
to  Armour  Institute. 


88 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  4. — Panel  4 — Results  of  compression  tests  made  on  portions  of  one-piece  single- 
air-space  mortar  building  blocks  after  fire  test. 

<*  DAMP  BLOCKS. 

[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts 
la 

No.  of 
pieces 
crushed. 

sand  to  1  of  Port- 
nd  cement. 

No.  of 
pieces 
crushed  . 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

•      2 
3 
2 
2 
'2 
1            1 

2,219 

902 

2 

369 

2  

2,375 

1,903 

1 

596 

3 

1,950 

Average 

1,462 

3           571 

1,422 

2,181 

512    

MEDIUM  BLOCKS. 


/           2 

1,795 

2 

1,280 

2 

1           2 
1           2 

1,939 

2,639 

1 
2 

979 

"~i~735' 

2 

632 

579 

3 

1           2 
/            2 

2,123 

2,494 

2 
2 

1,032 

1,^36 

3 
2 

568 

722 

\           1 

1,476 

1 

1,604 

3 

650 

Average.  . 

1,846 

2,309 

1,205 

1,484 

617 

651 

WET  BLOCKS. 


/           2 

2,504 

2 

1,553 

i       i 

1,762 

2 

1,596 

/           2 

2,231 

2 

1,640 

\           2 

1,454 

1 

689 

)           2 

2,196 

2 

1,361 

\           1 

2,312 

2 

1  434 

Average  

1,843 

2,310 

1,240 

1  518 

a  Blocks  of  8  parts  sand  to  1  of  Portland  cemen  were  destroyed  in  transit  from  Underwriters'  Laboratories 
to  Armour  Institute. 


RESULTS    OF   TESTS. 


89 


TABLE  5. — Panel  5 — Results  of  compression  tests  made  on  portions  of  one-piece  single- 
air-space  mortar  building  blocks  after  fire  test. 


DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Average 
strength. 
No.  of 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

pieces 
crushed.     Ex- 

"rSd 

Un- 
exposed 
face. 

1  

•!     J 
{     ! 
{     J 

1,914 

1 
2 
1 
1 
1 
2 

906 

1  1  

405 

2 

1,581 

810 

774 

sol 

1,825 

1,246 

3  

\  VPrAfTP 

975 

507 

1           408 

1,034 

1,773 

466 

987 

408 

405 

_   1 

MEDIUM  BLOCKS. 


1...           ...{     J 

1,492 

»i  

1,242 

1 

592 

I           2 
/            1 

1,577 

2,152 

3           655 

658 

1 

615 

1,014 

••  \           2 
3                                     1            i 

1,406 

2,498 

'2           709 

628 

2 
1 

822 

1,005 

••\           2 

1,464 

1           958 

1 

559 

Average                ...  . 

1,482 

2,047 

...I        774 

843 

665 

870 

! 

WET  BLOCKS. 


1                   

/      ; 

2,632 

1 

2,861 

1 

1,039 

2  

I            2 
1           2 

1,786 

3,066 

2 

1 

1,652 

1,459 

3 
1 

843 

781 

3  

I            2 

|            1 

2,781 

1,857 

2 

1 

1,441 

1,880 

3 
1 

628 

997 

I           2 

1,780 

1,533 

1 

542 

\verage 

2  116 

2  518 

1  542 

2  067 

671 

939 

90 


FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  6. — Panel  6 — Results  of  compression  tests  made  on  portions  of  one -piece  single- 
air-space  mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

/           3 
\           2 
j- 

1,189 

3 

2 
2 

740 

729 

1 

385 

2  

688 

2 

108 

3     -               

>           ? 

3 
1 

571 

1 

265 

Average 

I  

1,141 

1,189 

505 

663 

353 

MEDIUM  BLOCKS. 


J 

3 

1,466 

2 

990 

1    

406 

2  

2 
3 

1,687 

~"i,'538" 

1 

2 

731 

1,304 

2    

515 

3  

2 

837 

3    

833 

I 

2 

1,413 

2 

1,081 

Average 

1,550 

1,502 

922 

1,044 

1 

585 

1 

WET  BLOCKS. 


f           2 

2,794 

2 

827 

\ 

2 

643 

2  

/  3 

2,000 

3 

1,105 

2 

991 

I           2 
\  

2,215 

2 

2 

1,034 

1,111 

2 

718 

521 

v 

2 

1,291 

2 

697 

... 

Average  

2,215 

2,397 

1,163 

1,108 

686 

780 

RESULTS   OF   TESTS. 


91 


TABLE  7. — Panel  7 — Results  of  compression  tests  made  on  portions  of  one-piece  single- 
air-space  mortar  building  blocks  after  fire  test. 


DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 

pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

I 

{     i 
{     I 
{     \ 

1,681 

2 
2 
2 

'"444" 

493 
""599 

1,213 

1,432 

2 

•I 

2 
2 

485 

758 

3  

1,390 

6U 

1,119 

4/1 

1 
2 

816 

Average 

1,153 

1,411    578 

1                      ! 

615 

502 

636 

MEDIUM  BLOCKS. 


1 

1  { 

1,603 

2 

1,226 

.1  

845 

\     2 
2...           ...{ 

1,475 

1,710 

2 
1 

111 

987 

3    730 
2  

858 

1      2 

•j                ]     2 
A  K 

1,366 

1,331 

2 

1,265 

3  

927 

p   l 

1  370 

1  548 

974 

1  159 

509 

877 

' 

WET  BLOCKS. 


2 

2,068 

2 

931 

2 

927 

1  

2 

2  161 

2       1,115 

2 

552 

2 

2 

2,490 

2  i  

1,113 

2 

963 

2 
2 

1,877 

2  843 

2  j        866 

2  i 

1,086 

2 
2 

544 

9i6 

3  

o  oqi 

2  '        802 

2 

467 

Average           > 

2,143 

2,467 

928 

1,043 

521 

933 

1 

92 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  8. — Panel  8 — Results  of  compression  tests  made  on  portions  of  one-piece  single- 
air-space  mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 

[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 

pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1       

/           2 

4 

978 

1 
2 
1 
3 
1 
2 

"'636' 
'i',170 

834 
"'i',077' 

1 
1 
1 
2 
1 
1 

321 

2 

1,255 

431 

545 

3 

\           2 
1            2 
I           2 

868 
~'i,'48~2" 

1,437 

612 

263 

249 

Average 

571 

228 

1,202 

1,208 

792 

841 

307 

372 

MEDIUM  BLOCKS. 


1  

/      5 

3,000 

2 

908 

2 

823 

2 

I     i 

2,008 

2,302 

2 

1 

764 

1,053 

2 
1 

514 

393 

3  

\           2 
{            \ 

1,784 

2,583 

2 
1 

778 

""549" 

2 
1 

476 

'724 

I            1 

Average 

1  812 

2  628 

800 

837 

495 

647 

WET  BLOCKS. 


1  

2 

4,046 

1 

1,805 

1 

923 

2  

2 

1  ,  777  . 

"~"3,"253" 

3 
1 

1,903 

1 

946 

3  

2 

2 

2,159 

2,623 

2 

1 

909 

2,059 

2 
1 

503 

'"753 

2 

1,683 

1 

1,415 

2 

485 

Average 

1  873 

3  307 

1  204 

1  922 

539 

874 

RESULTS   OF   TESTS. 


93 


TABLE  9. — Panel  9 — Results  of  compression  tests  made  on  portions  of  two-piece  morjar 
building  blocks  after  fire  test. 


DAMP   BLOCKS. 
[In  pounds  per  square  inch.  ] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

o 

{      l 

1 

659 

1 

300 

1 

1 

449 

1           2 
1  2" 

2 

896 

1    

223 
""423 

X.. 
Y 

1,007 

1,219 
1,313 

1          350 

4 

1 

899 

Average  

952 

1,242 

350 

669 

315 

I 

MEDIUM  BLOCKS. 


f            1    .                      1,174                1 

1 

1,027    

1  \            i           702                                   2 

743 

f            1     1,205                1 
z  )            2       1,423                                   2 

693 

535                1    

502 

/I                           1  206                1 

576 

8  i             2        1,478                                     2 

971 

3           552 

X                                                1                           1  891                3 

1  133 

Y  1                           1,315                1 

1,388                2    

727 

Vverage                                    1  201  I        1  358 

802 

932                            552 

615 

WET  BLOCKS. 


{     i 

860 

1,214 

1 
2 

1  113 

872 

1  

531 

2  

I  ; 

756 

1 

1,254 

1  I  

528 

3 

} 

1,745 

1  

429 

X  . 

'  if 

1,671 

1  554 

1 

1,461 

2  '.'. 

530 

Y  . 

1 

1  455 

1 

1  305 

2  . 

623 

Average 

1  244 

1  345 

992 

1,223 

528 

94 


FIRE   RESISTANCE    OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  10. — Panel    10 — Results   of  compression  tests   made  on  portions  of  two-piece 
mortar  building  blocks  after  fire  test. 

DAMP  BLOCKS. 
[In  pounds  per  square  inch.] 


Block  No. 

2  parts  sand  to  1  of  Port- 
land cement. 

4  parts  sand  to  1  of  Port- 
land cement. 

8  parts  sand  to  1  of  Port- 
land cement. 

No.  of 
pieces 
crushed. 

Average 
strength. 

No.  of 
pieces 
crushed. 

Average 
strength. 

Average 
strength. 
No.  of 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

Ex- 
posed 
face. 

Un- 
exposed 
face. 

pieces 
crushed.     Ex- 
posed 
face. 

Un- 
exposed 
face. 

1  

/           1 
\          2 

{      I 

1           1 
I           2 

3 

'   ~543 

920 

j 

2  |        473 
1  i  

2           470 

2 

600 

536 

3 

377 

1,034 

X 

47i 

987 

4    

537 

Y 

Average 

ii^ir: 

m 

885 

472 

537 

MEDIUM  BLOCKS. 


1  

I         a 

1.153 

1 



890 

2 

I           2 
(           I 

804 

845 

1 

1,231 

\           2 
/  

7ie 

1 
1 

374 

1,251 

1 

490 

3  

\           2 

470 

2 

235 

X  . 

1 

1.381 

2 

. 

1,085 

1 

321 

Y 

2 

1  633 

3 

1  192 

Average  .  . 

663 

1  253 

348 

1,132 

406 

WET  BLOCKS. 


f          1 

1,595 

1 

1,015 

1 

CGI 

I           2 

866 

3 

435 

2 

407 

2  

{           } 

1,228 

1 

1,314 

1 

528 

3  

1            2 
1 

900 

""i,"686* 

2 
1 

687 

1,493 

1 
1 

523 

""863 

X.. 

1            * 

2 

1  460 

Y  

1 

1,365 

2 

823 

Average  .  .  . 

788 

1  503 

622 

1  329 

398 

719 

RESULTS   OF   TESTS. 


95 


TABLE  11. — Panel  11 — Physical  properties  of  brick  before  firing. 


Under  normal  conditions. 

Immersed  in  water 
48  hours. 

Water  absorption,  brick  i 
not  fired. 

Trans  vers 
brick  n 

Breaking 
load. 

' 

a  strength, 
>t  fired. 

Compressive  strength  per 
square  inch. 

Com- 
pressive 
strength 
per 
square 
inch, 
brick 
not 
fired. 

Reduc- 
tion in 
strength 
in  pounds 
per 
square 
inch. 

30  min- 
utes. 

4 

hours. 

48 
hours. 

Modulus 
of 
rupture. 

Brick 
from 
exposed 
face. 

Brick 
from 
center 
of  wall. 

Brick 
from 
back 
of  wall. 

Brick 
not 
fired. 

Pounds. 
1,056 
1,280 

435 

528 

Pounds. 
2,505 
3.190 
2,498 
3,160 
2,018 
2,452 
3,718 
2,970 
2,290 
2,890 
2,919 
2,655 
3,042 

Pounds. 
2,420 
2,865 
2,034 
1.996 
2,180 
2,592 
2.922 
2,610 
2,595 
2,810 
2,180 
2,990 

Pounds. 
2,912 
2,648 
2,420 
2,705 
2,946 
2,701 
3,435 
2,580 
2,330 
2,470 
2,430 
2,202 

Pounds. 
2,711 
2,977 
2,110 
2.963 
2,460 
3,272 
3,342 
3.239 
2,684 
1,393 
2,870 

Pounds. 
2,100 
2,100 

Per  cent. 
26.5 
29.6 

Per  ct. 
20.0 
16.5 

Per  ct. 
20.9 
17.2 

Per  ct. 
22.0 
18.3 

Aver.  .  .            482 

2,793 

2,516 

2,648       2,729  :        2,100 

28.1 

18.0         19.1 

20.2 

TABLE  12. — Panel  12 — Physical  properties  of  hydraulic-pressed  brick  before  firing. 


Normal. 

Immersed  in  water 
for  48  hours. 

Water  absorption. 

Transverse 
strength,  brick 
not  fired. 

Compressive 
strength  per 
square  inch. 

Compressive 
strength  per 
square  inch. 

Increase  in 
Compressive 
strength. 

39  minutes. 

4  hours. 

48  hours. 

Break- 
ing 
load. 

Modu-      Ex- 
lus  of  j  posed 
rupture.1  face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face.. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 

posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Lbs. 
1,805 
1,796 

720 
716 

Lbs. 
4,067 
2,702 
3.150 
3  480 

Lbs. 
4,320 
5,830 
3.600 
5.560 

Lbs. 
2,923 
3,810 

Lbs. 
4,995 
3,881 

P.ct. 

P.ct. 

P.ct. 
9.9 
11.2 

P.ct. 
10.6 
10.7 

P.ct. 
10.5 
11.2 

P.ct. 
10.6 
10.8 

P.ct. 
10.5 
11.2 

P.ct. 
10.6 
10.8 



4,290     3.190 
2,590     5.040 
3,480     3.420 
3.  180     4.  100 
4,110  i  4.22O 







4,710 
5,220 
4.600 

5.720 
3.710 
3,830 
5.640 





-9.1 

Aver.         718 

3,701 

4,440     3,367 

4,438 

-0.  1     10.  6 

10.7 

10.9 

10.  7     10.  9     10.  7 

96 


FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 


TABLE  13. — Panel  22 — Physical  properties  of  common  clay  brick  before  firing. 
[No  fired  bricks  were  tested.] 


Normal. 

Immersed   in   water   for 
48  hours. 

Water  absorption. 

Transverse 
strength. 

Compressive 
strength  per 
square  inch. 

Compressive 
strength  per 
square  inch. 

Increase  in 
Compressive 
strength. 

30  minutes. 

4  hours. 

48  hours. 

Break- 
ing 
load. 

Modu- 
lus of 
rup- 
ture. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex- 
posed 
face. 

Unex- 
posed 
face. 

Ex-     Unex- 
posed  posed 
face.  ,    face. 

Lbs. 
5,368 
3,442 
3,892 
3,302 
1,367 

Aver. 

1,819 
1,167 
1,320 
1,119 
463 

Lbs. 

Lbs. 
5,563 
2,608 
2,762 
3,466 

Lbs. 

Lbs. 
6,850 

P.ct. 

P.ct. 
23.1 
292.0 
68.3 
98.0 
1.3 

P.ct. 

P.ct. 
8.5 
1.6 

P.  ct. 

P.ct. 

8.5 
2  8 

P.  ct.     P.  ct. 

8  7 



10,230 
4,650 
6,860 
4,867 

4  6 

4.7 

5.8 
6.0 
4.8 

6.5 

3.8 

4  7 

6  6 

4,930 

4.  8 

1,178 



3,866 

6,691    96.0 

4.7 

5.6 

6.2 

1 

TABLE  14. — Panel  29 — Physical  properties  of  sand-lime  brick  before  and  after  firing. 


Normal. 

Immersed  in  water 
for  48  hours. 

Water  absorption. 

Transverse  strength  . 

Com- 
pressive 
strength 
per 
square 
inch. 

Com- 
pressive 
strength 
per 
square 
inch. 

Reduc- 
tion in 
com- 
pressive 
strength. 

30  min- 
utes. 

4  hours. 

48  hours. 

Breaking 
load. 

Modulus 
of  rup- 
ture. 

Not  fired  

Average  .  . 

Brickfrom  back 
of  wall  

Average.. 

Brick  with  ends 
exposed  

Average.. 

Brick  with  face 
exposed  

Average.. 

Pounds. 
\         913 
909 
797 
684 
695 

364 

362 
318 
273 
111 

Pounds. 
2,020 
2,510 
2,161 
1,923 
1,562 

Pounds. 
1,816 
1,636 
1,604 
1,382 
963 

Per  cent. 
10.1 
34.8 
25.8 
28.1 
38.3 

Per  cent. 
16.33 
16.30 
9.81 
18.22 
13.04 

Per  cent. 
16.59 
16.60 
13.62 
18.29 
13.91 

Per  cent. 
16.59 
16.  60 
13.62 
18.29 
14.28 

800 

-319 

2,035 

1,480 

27.4 

14.74 

15.80 

15.88 

642 
841 
770 
789 
645 

256 
336 
308 
315 
258 

2,117 
2,109 
1,208 
2,430 
1,790 

1,261 
976 
1,451 
1,  468 
873 

40.5 
53.7 
a  20.0 
39.6 
52.2 

15.30 
11.90 
13.72 
13.80 
16.92 

15.3 
13.45 
15.79 
14.30 
16.92 

15.3 
14.00 
15.79 
14.30 
16.  92 

737 

295 

1,931 

1,206 

33.2 

14.33 

15.15 

15.26 

494 
756 
707 
463 
551 

197 
302 
282 
185 
220 

1,952 
2,176 
2,109 
1,306 
1,541 

1,189 
826 
1,157 
1,444 
1,289 

39.1 
62.0 
45.0 
a  10.  5 
16  4 

14.65 
12.30 
13.90 
12.00 
10.40 

14.65 
13.20 
13.90 
13.80 

12.87 

14.65 
13.20 
13.90 
13.80 
12.87 

594 

237 

1,817 

1,181 

30.4 

12.65 

13.  68 

13.68 

1,112 
1,794 
1,827 
1,994 
2,024 

838 
1,384 
902 
1,270 
1,536 

24.7 
22.8 
50.6 
36.3 
24.1 

19.11 
12.70 
18.50 
16.60 
12.82 

19.30 
13.91 
18.80 
16.60 
13.83 

19.30 
14.17 
18.80 
16.91 
14.21 

127 
117 
126 

58 
53 

58 

123 

56 

1,750 

1,186 

31.7 

15.95 

10.  49 

16.68 

Increase. 


BIBLIOGRAPHY. 


SURVEY  PUBLICATIONS   ON   STRUCTURAL  MATERIALS. 

The  following  reports  of  the  Geological  Survey  relate  to  structural 
materials,  etc.  A  copy  of  any  except  those  that  are  priced  can  be 
had  free  by  applying  to  the  Director,  U.  S.  Geological  Survey,  Wash- 
ington, D.  C.  The  others  can  be  obtained  by  sending  price,  in  cash, 
to  Superintendent  of  Documents,  Government  Printing  Office,  Wash- 
ington, D.  C. 

BULLETIN  243.     Cement  materials  and  industry  of  the  United  States,  by  E.  0.  Eckel. 

1905.     395  pp.,  15  pis.     65c. 
BULLETIN  260.     Contributions  to  economic  geology,   1904.     The  American  cement 

industry,  by  E.  C.  Eckel,  pp.  496-505.     1905.     40c. 
BULLETIN  324.     The  San  Francisco  earthquake  and  fire  of  April  18,  1906,  and  their 

effects  on  structures  and  structural  materials,  by  G.  K.  Gilbert,  Richard  L. 

Humphrey,  J.  S.  Sewell,  and  Frank  Soule.     1907.     170  pp.     50c. 
BULLETIN  329.     Organization,  equipment,  and  operation  of  the  structural  materials 

testing  laboratories  at  St.  Louis,  by  Richard  L.  Humphrey.     1908.     85  pp. 
BULLETIN  331.     Portland  cement  mortars  and  their  constituent  materials;  results 

of  tests  made  at  the  structural  materials  testing  laboratories,  St.  Louis,  Mo., 

by  Richard  L.  Humphrey  and  William  Jordan,  jr.     1908.     130  pp. 
BULLETIN  340.     Contributions  to  economic  geology,  1907,  part  1.     Cement  and  con- 
crete materials,  by  E.  F.  Burchard  and  G.  B.  Richardson,  pp.  383-416.     1908. 
BULLETIN  344.     The  strength  of  concrete  beams;  result  of  tests  made  at  the  structural 

materials  testing  laboratories,  St.  Louis  Mo.,  by  Richard  L.  Humphrey.     1908. 

58pp. 
WATER-SUPPLY  PAPER  143.     Experiments  on  steel-concrete  pipes  on  a  working  scale, 

by  J.  H.  Quinton.     1905.     61  pp.,  4  pis.     5c. 
MINERAL    RESOURCES   U.  S.  for  1901  (70c),  1902,   1903  (70c),  1904,  1905  ($1),  and 

1906  (50c).     Contains  statistics  of  production  of  building  stones,  cement,  and  clay. 

The  volume  for  1906  contains  Advances  in  cement  technology,  by  E.  C.  Eckel. 

pp.  897-905. 
PROFESSIONAL  PAPER  11.    The  clays  of  the  United  States  east  of  the  Mississippi 

River,  by. H.  Ries.     1903.    298pp.    40c. 
SIXTEENTH  ANNUAL  REPORT,  pt.  4.     Technology  of  the  clay  industry,  by  H.  Ries, 

pp.  523-575,  4  pis.     1895.    $1.20. 

FIRE  TESTS   OF   STRUCTURAL,  MATERIALS. 

The  following  papers  contain  mention  of  most  of  the  fire-resistive 
tests  of  structural  materials  made  since  1890  that  have  been  de- 
scribed in  the  technical  press: 

HIMMELWRIGHT,  A.  L.  A.  Fireproof  construction.  Eng.  Mag.,  vol.  12,  1896,  pp. 
460-469.  Describes  seven  tests  on  different  types  of  floors  by  the  New  York 
Department  of  Buildings. 

73087— Bull.  370—09 7  97 


98  FIRE   RESISTANCE   OF   VARIOUS   BUILDING   MATERIALS. 

MCFARLAND,  H.  B.  Tests  of  the  effects  of  heat  on  reinforced  concrete  columns. 
Eng.  News,  September  20,  1906,  pp.  316-318. 

McKiBBEN,  F.  P.  Fire  and  weight  test  of  Columbia  fireproof  floor.  Eng.  News, 
November  21,  1904,  p.  378.  Describes  test  of  floor  of  reinforced  stone  concrete 
having  veneer  of  cinder  concrete. 

SACHS,  E.  O.  Facts  on  fire  prevention.  The  result  of  tests  conducted  by  the  British 
Fire  Prevention  Committee.  London,  1902.  Vol.  1,  219  pp.;  vol.  2,  226  pp. 
Tests  of  materials,  vol.  2,  deal  chiefly  with  tests  of  various  types  of  floors,  ceilings, 
and  partitions. 

WILLEY,  D.  A.  The  Underwriters'  Laboratories.  Sci.  Am.  Supp.,  August  22,  1903, 
pp.  23109-23110.  Brief  description  of  plant  and  work. 

WOOLSON,  IRA  H.  Tests  of  the  strength  and  fireproof  qualities  of  sand-lime  brick. 
Trials  under  the  requirements  of  the  New  York  Bureau  of  Buildings,  made  at 
Columbia  University.  Eng.  News,  June  14,  1906,  pp.  662-664. 

Investigation  of  the  effect  of  heat  upon  the  crushing  strength  and  elastic 
properties  of  concrete.  Eng.  News,  July  13,  1905,  pp.  35-38.  Describes  labora- 
tory experiments  at  Columbia  University,  on  trap  rock  and  limestone  aggregates. 
Abstract  of  paper  before  Am.  Soc.  Testing  Mat. 

Investigation  of  the  thermal  conductivity  of  concrete  and  the  effect  of  heat 


upon  the  strength  and  elastic  properties.  Eng.  News,  June  28,  1906,  pp.  723-725. 
Abstract  of  paper  before  Am.  Soc.  Testing  Mat.  Describes  laboratory  tests  of 
limestone,  trap,  cinder,  and  gravel  aggregates  at  Columbia  University. 

AMERICAN  ARCHITECT.  Fireproof  construction  tests.  March  28,  1891.  Describes 
tests  at  Denver,  Colo. 

ENGINEERING.  The  results  of  some  tests  with  fire-resisting  material.  November  1.7, 
1905,  p.  646.  Describes  tests  and  experiments  of  British  Fire  Prevention  Com- 
mittee with  concrete  and  reinforced  concrete  floor  arches. 

ENGINEERING  NEWS.  Tests  of  material  for  fireproofing  columns.  September  (>, 
1894,  p.  184.  Gives  results  of  tests  at  Vienna. 

-  Tests  of  fireproof  material.     September  17,  1896,  pp.  182-183.     Comparison 
of  concrete  and  hollow  tile  by  New  York  Department  of  Buildings. 

-  Tests  of  fireproof  floor  construction.     April  22,  1897,  pp.  255-256.     Describes 
tests  of  reinforced  concrete  systems. 

Tests  of  fireproof  partitions  by  the  New  York  Department  of  Buildings.     De- 


cember 26,  1901,  pp.  482-486.  Describes  thirteen  tests  of  mortar  and  plaster 
blocks,  concrete  blocks,  terra  cotta,  and  protected  metal  strips  and  metal  lath. 

Tests  of  vulcanite  floors.  February  8,  1902,  p.  116.  Describes  tests,  at  Phil- 
adelphia, of  a  steel  and  concrete  construction. 

Fire  tests  of  fireproof  floors  by  the  New  York  Department  of  Buildings.  May 
29,  1902,  pp.  441-442.  Gives  construction  of  various  types  tested  at  Brunswick, 
N.J.,  byF.  C.  VanDyck. 

Tests  to  determine  the  fire  resistance  and  heat  conductivity  of  concrete. 
August  3,  1905,  pp.  115-116.  Abstract  of  report  to  National  Fire  Protection  Asso- 
ciation on  tests  of  beams  made  of  limestone,  gravel,  and  cinder  aggregates. 

Fire  tests  of  reinforced  concrete  floors.  February  1,  1906,  p.  115.  Describes 
tests  at  Brunswick,  N.  J.,  by  F.  C.  Van  Dyck,  of  reinforced  cinder-concrete  slab 
and  steel  I-beam  construction  and  of  reinforced  stone-concrete  slab  and  girder 
construction . 

Fire  tests  of  a  fireproof  floor  with  bays  of  different  aggregates.  February  1, 
1906,  p.  116.  Gives  results  for  seven  aggregates. 

Comparative  resistance  to  fire  of  concrete  and  cinder  concrete.  May  31,  190G, 
p.  603.  Tests  by  British  Fire  Prevention  Committee,  of  gravel  concrete  and 
clinker  and  coke  breeze  concrete. 


BIBLIOGRAPHY.  99 

ENGINEERING  RECORD.      Fireproof  construction.     April  4,  1891,  p.  288.     P^ditorial 
on  Denver  te.^i.-. 

Tests  of  fireproof  arches  at  St.  Louis.     May  7,  1892,  pp.  376-377.     Describes 
tests  of  different  concrete  constructions. 

Fireproof  construction.     October  7,  1893,  p.  14.     Mentions  various  types  of 
floors  and  doors  tested  at  Berlin. 

The  best  fireproof  construction  for  buildings  occupied  for  mercantile  purposes. 
October  9,  1897,  pp.  495^98. 

— •-  Official  test  of  fireproof  floor  construction  systems.  September  18,  1897,  pp. 
337-340;  September  25,  pp.  359-363;  October  2,  pp.  382-387;  October  9,  pp. 
403-408.  Describes  tests  of  fourteen  floor  systems  by  the  New  York  Department 
of  Buildings  in  1896-97.  Tests  were  in  kilns  over  wood  fires. 

Tests  of  a  new  system  of  terra-cotta  floors.     February  25,  1905,  pp.  220-221. 


Describes  tests  of  floor  to  be  used  in  forty  warehouses  under  construction  in  Pitts- 
burg.     Report  by  Ira  H.  Woolson. 

IKXTIFIC  AMERICAN  SUPPLEMENT.  The  British  Fire  Prevention  Committee  and 
its  work.  June  20,  1903,  pp.  22959-22960.  Describes  testing  equipment  and 
scope  of  work. 

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